There is no origin to Krsna's marginal energy (unlimited individual eternal jiva-souls), who have ALWAYS existed like Krsna has always existed.

The individual jiva-souls are eternal “persons” as a spiritual bodily form.

This means each individual jiva-soul (marginal living entity) has their own unique eternal spiritual body, personality and free will, that allows them to voluntarily serve Krsna in 5 different ways in unlimited pastimes.

The eternal spiritual form of the jiva-soul is NOT a spark in Krsna's Bodily effulgence (which is a fallen condition of the jiva-soul), it is an eternal bodily form-

sat, 

cit, 

ananda, 

vigraha.

These word's means- 

eternity, 

knowledge, 

bliss, 

form.

The jiva-souls have eternally existed without any beginning point or ending point, this means no jiva-souls have originated from anywhere, including- 

1 - The impersonal Brahmajyoti.

2 - The Body of Maha-Visnu.

3 - A dormant (inactive) region called tatastha-sakti.  

All the above are “conditioned states” outside of the spiritual world, where the jiva-souls fall down to. 

The jiva-souls are part and parcel of Krsna's eternal “marginal energy” however, the marginal energy or potency is NOT a place where the jiva-souls have originated from, it simply means the jiva-souls can be under the influence of the spiritual realm or under the influence of the material realm.  

There is no origin to Krsna's marginal energy (unlimited individual eternal jiva-souls), who have ALWAYS existed like Krsna has always existed. 

The marginal platform means the eternal jiva-souls belong to that category of marginal living entities (meaning they are influenced by either the spiritual energy, or material energy eternally), explained as follows by Prabhupada.

Srila Prabhupada – “The jiva-souls are Krsna’s marginal energy. Marginal energy means the jiva-souls may be under the control of the spiritual energy, or they may be under the control of material energy. But when the jiva-souls are under the control of the material energy, that is their precarious condition, struggle for existence. And when they are under spiritual energy, that is their original position and life of freedom.” (Los Angeles, Nov 23, 1968)

Therefore, being “generated” from the marginal plane does NOT mean “originating” from the marginal plain because there is no origin of the jiva-souls, they are ETERNALLY part and parcel of the marginal plain that has always existed and has no origin.

The word “marginal” simply means the jiva-souls exist sometimes under the influence of the spiritual energy, or sometimes under the material energy.

Srila Prabhupada – “The jiva-souls are Krsna's marginal energy. Marginal energy means we can live either in this external energy or in the internal energy, in between. So at the present moment we are living in the external energy. But this external energy is also Kṛṣṇa's energies, God's energy. It is not different from Him. But the external energy means we are captivated by the external energy. But the external energy is not permanent. The internal energy is permanent. The spiritual world is permanent, and the jiva-souls are also permanent as Bhagavad Gita As It Is Chapter 2 text 20 (1983 edition) reveals.” (Lecture on BG 9.4 -Melbourne, April 23, 1976)

Bhagavad Gita As It Is Chapter 2 text 20 explains the jiva-souls have existed for “infinity” which means, just like Krsna, they are beginning less and endless, and were NEVER created-

“For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain.” (BG Ch 2 text 20 “corrected” 1983 edition)

Bhagavad Gita As It Is Chapter 2 text 12 also confirms the jiva-souls were NEVER created. 

This is because they have no origin and have existed for infinity like Krsna has, as Krsna explains-

“Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be.” (BG 2.12)

The jiva-souls and Kṛṣṇa have always existed.

Srila Prabhupada – “There are no new souls, new and old are due to this material body, but the jiva-soul is never born and never dies, so if there is no birth, how can there be new souls?” (Letter to Jagadisa dasa, 7/9/1970)

Srila Prabhupada – “Existence in the impersonal brahman is also within the category of non-Krsna consciousness. Those who are in the brahman effulgence are also in the fallen condition, so there is no question of falling down from a fallen condition. When fall takes place, it means falling down from the non-fallen condition. The non-fallen condition is Krsna consciousness.” (Letter to Revatinandana, Los Angeles 13 June, 1970)

Tatastha-sakti is an already fallen conditional state, as Prabhupada explains, so there is no question of falling down from an already fallen state.

Srila Prabhupada – “So this material world is the taṭastha (conditioned) characteristics, and the spiritual world is the “personal” characteristics. So our effort is to get out of this taṭastha (conditioned) characteristics and to enter the permanent characteristics. That is called spiritual elevation.” (Lecture on CC Madhya-lila 20.354-358 — New York, Dec 28, 1966)

Srila Prabhupada – “Because the individual soul is apt to fall down sometimes under the clutches of māyā, it is called taṭastha-śakti. Just like in the seaside the shore, the beach, sometimes you see it is covered by water and sometimes it is land; similarly, when we are covered by māyā, that is our jīva-bhūta stage, and when there is no more covering, that is brahma-bhūta stage. When we are Kṛṣṇa conscious, then we are brahma-bhūta (SB 4.30.20), and when we are not Kṛṣṇa conscious, we are materially conscious, that is māyā.” (Lecture on BG 7.4-5 - Bombay, March 30, 1971)

Fall down means from a none fallen condition and that none fallen original position of the jiva-souls is Vaikuntha and Goloka Vrindavana which are their perpetual homes.  

The “marginal living entities” are a collective of eternal individual jiva-souls who have no beginning nor were they ever created.

Srila Prabhupada – “The human form is the full manifestation of the jiva-soul.” (Melb, May 20, 1975)

Devotee – “Is the original body of the jiva-soul a human form?”

Srila Prabhupada – “Yes, human form. God is also human form. “Man is made after the shape of God.” I think there is in the Bible. Is it not? So God is also like human form, here you see Krsna, two hands, two legs.”

Hari-sauri – “How do we understand, then, that there are peacocks and flowers and trees in the spiritual world? Are these not eternal forms?”

Srila Prabhupada – “[describing material form first]: Yes, they are more covered, just like if you cover your body with blanket, the hands and legs are invisible. But you are not the blanket. So the trees and plants, they are more covered. They are not in full manifestation, the human form is the full manifestation of the jiva-soul.”

Hari-sauri – “They are covered in the spiritual world?”

Srila Prabhupada – “Not in the spiritual world, there that is voluntary. Some devotees want to serve Krsna as flower; then they become flower there, they lie down at the lotus feet of Krsna as a flower voluntarily, but he can change his form from flower to human body if one wants. That is spiritual life. There is no restriction. If some devotee wants to serve Krsna as cow, he serves Krsna as cow, as calf, as flower, as plant, as water, as ground, field, or as father, as mother, as friend, as beloved, anything. It is inconceivable, yet a fact.” (SB, Canto  6.1.1-4 - Melb, May 20, 1975)

Fortunately, over 90% of jiva-souls choose to stay in the spiritual world's of Vaikuntha and Goloka-Vrindavana, even though they can choose to leave if they want. 

However, sadly, almost 10% do choose to leave and enter the material creation via the dreams of Maha-Visnu.

The jiva-souls have the free will to make their own choices which includes even rejecting Krsna. For free will to truly exist, this choice also must be an option.

In the spiritual worlds the jiva-soul's relationship with Krsna is always voluntary.

Their individual contributions are eternally expressed in both Vaikuntha and Goloka-Vrindavana in a two-way reciprocal exchange with Krsna.

In the spiritual worlds the jiva-souls are never forced to surrender to Krsna or do anything they choose not to do. 

For loving service and exchanges to truly exist, the individual jiva-souls must be able to act on their free will and make their own choices, decisions and offerings, even if it also means rejecting Krsna if they choose, otherwise there can be no question of voluntary loving exchanges.

Each jiva-soul can voluntarily express themselves as an independent individual to experience unique loving exchanges and personal service.

Srila Prabhupada – “So, unless there is a possibility of misusing our free will, there is no question of freedom.” (Dialectical Spiritualism, Critique of Descartes)

This quality of free will is part and parcel of the jiva-soul's marginal constitution that allows them to be an independent free thinking expansion of the Krsna. 

Therefore, being marginal (jiva-soul) also means having free will that is included when describing the qualities of the individual jiva-souls. 

As said above, Krsna allows this freedom the jiva-souls have because without free will, loving exchanges, personal offerings and a two-way reciprocal relationship could never exist.

Srila Prabhupada – “You have got little independence therefore you can violate. Because you are part and parcel of God you have got independence, proportionately, therefore if he likes he can return to the material atmosphere. That independence has to be accepted, little independence. We can misuse that.” (Mayapur, Feb 19, 1976)

Having free will is the constitutional make up of all marginal living entities (jiva-souls) that is eternally part and parcel of their individual character and personality in the spiritual worlds.

This means the jiva-souls can choose to leave the Vaikuntha planets or Goloka-Vrindavana if they choose, at anytime, it is nonsense to claim the jiva-souls can never again fall down once in Vaikuntha or Goloka-Vrindavana.

This is because free will always allows the jiva-souls to have a choice.

Therefore, without the ability to voluntarily choose, there is no question of experiencing loving exchanges.

So, the choice to even leave Vaikuntha or Goloka Vrindavana is possible, because Krsna allows a two-way relationship where one can accept or reject Krsna if they choose.

Srila Prabhupada – “Free will means that you can act wrongly. That is free will, unless there is chance of doing wrong or right, there is no question of free will. Where is free will then? If I act only one sided, that means I have no free will. Because we act sometimes wrongly, that means free will.”

Hayagriva – “A man may know better but still act wrongly.”

Srila Prabhupada – “Yes, but that is free will He misuses his. Just like a thief, he knows that his stealing is bad but still he does it. That is free will. He cannot check his greediness, so in spite of his knowing that he is doing wrong thing—he will be punished, he knows; he has seen another thief, he was punished, he was put into prison— everything he knows, but still he steals. Why? Misuse of free will. Unless there is misuse of free will, there is no question of free will.” (Talk about Rene Descartes)

There is only one classification of jiva-souls, not two as some believe. 

Therefore, each individual jiva-soul has "two-sides" to their personality, they can either be “nitya-baddha” (eternally conditioned), or can be “nitya-siddha” (eternally liberated)

In this way, the jiva-souls can choose for themselves to be with Krsna, or reject Krsna.

The fact is, each jiva-soul, as part of their spiritual constitutional make-up, has free will.

How can there be voluntary love with Krsna without free will?

Srila Prabhupada – “So, unless there is a possibility of misusing our free will, there is no question of freedom.” (Dialectical Spiritualism, Critique of Descartes)

Srila Prabhupada – “So everyone can know that independence means one can use it properly, or one can misuse it. That is independence. If you make it one way only, that is not independence; that is force.” (Los Angeles, June 23, 1975)

Some “wrongly” claim there are two types of jiva-souls called “nitya-siddha” and “nity-baddha” which is incorrect. 

1 - The jiva-soul stays in the Vaikuṇṭha and Goloka-Vṛndāvana as nitya-siddha (eternally liberated), and can never have a choice to go to the material creation. Therefore, the jiva-souls can never again fall down to the material world once in the spiritual world.

2 - The other is the jiva-soul being nitya-baddha (eternally conditioned) in the material creation, or can also be dormant (inactive) in the impersonal Brahmajyoti. But can latter enter the spiritual worlds too, but once there, some claim, can never fall down. 

Such a division of the jiva-soul explained above is bogus nonsense.

There is only one category of jiva-soul who has two-sides to their individual personality, they can be nitya-siddha (eternally liberated) or nitya-baddha (eternally conditioned) 

The jiva-soul's original position is nitya-siddha (eternally liberated)

So where is the jiva-soul's original position? Where are they all coming from?

Srila Prabhupada – “In the broader sense everyone comes from Krsnaloka (Goloka-Vrindavana). When one forgets Krsna he is conditioned (nitya-baddha), when one remembers Krsna he is liberated (nitya-siddha).” (Letter to Mukunda, June 10, 1969)

As said above there is only one category of the jiva-souls that can be either nitya-baddha (eternally conditioned) or nitya-siddha (eternally liberated) 

Srila Prabhupada – “The answer to your question about the marginal energy is that the jiva-soul is always called the marginal energy whether he is in the spiritual world or in the material world.” (Letter to Rayarama, Dec 2, 1968)

This point is emphasised here to make it clear only one kind of jiva-soul exists and due to having free will, can choose to be either nitya-siddha or nitya-baddha.

As said above, there is only one category of jiva-soul that can be either (by choice) nitya-siddha (eternally liberated) or nitya-baddha (eternally conditioned)

Srila Prabhupada – “In the broader sense everyone comes from Krsnaloka. When one forgets Krsna he is conditioned (nitya-baddha), when one remembers Krsna he is liberated (nitya-siddha).” (Letter to Mukunda, June 10, 1969)

Srila Prabhupada – “There are two kinds of marginal living entities: nitya-siddha and nitya-baddha. The actual constitutional position of every marginal living entity is nitya-siddha.” (C.C. lecture, July 13, 1976) 

Srila Prabhupada – “By following the rules and regulations and instructions of the spiritual master, he can become again nitya-siddha. So the Krsna consciousness movement is to make the nitya-baddhas AGAIN nitya-siddha.” (New York Lecture on CC, July 13, 1976)

Srila Prabhupada – “So the Krsna consciousness movement is to make the nitya-baddhas AGAIN nitya-siddha, to bring them to their original position. It is a difficult task.” (London lecture on BG, 13-14, July 14, 1973)

Srila Prabhupada – “There are three kinds of liberated persons. They are called 1) sadhan siddha, 2) kripa siddha, and 3) nitya siddha. When one is actually on the siddha platform there is no such distinction as to who is sadhan, kripa, or nitya siddha. When one is siddha, there is no distinction what is what. Just like when the river water glides down to the Atlantic Ocean nobody can distinguish which portion was the Hudson River or some other river.” (Letter to Mukunda, June 10, 1969)

Srila Prabhupada - Nitya-baddhas are within this material world. Beginning from Brahma down to a small ant, insignificant ant, they are all nitya-baddha. Anyone who is in this material world they are nitya baddha.” (Lecture on BG, 13-14, July 14, 1973)

Srila Prabhupada – “We cannot say therefore that we are not with Krsna. As soon as we try to become Lord, immediately Maya covers us. Formerly we were with Krsna in His lila or sport. But this covering of Maya may be of very, very, very, very long duration; therefore many creations are coming and going.” (Letter to Madhudvisa Swami June 1972 Australia)

Srila Prabhupada – “Regarding your questions about how and from where did the conditioned souls fall, your first question if someone has a relationship with Lord Krsna on Krsnaloka (Goloka Vrindavana), does he ever fall down? 

The souls are endowed with minute independence as part of their nature and this minute independence may be utilized rightly or wrongly at anytime, so there is always a chance of falling down by misuse of one’s independence.” (Letter to Jagadisa dasa 4/25/1970)

Srila Prabhupada – “These spirit souls and all spirit souls are coming from Vaikuntha, but in these material worlds they are taking various grades of bodies according to their material activities. There is no new souls. New and old are due to this material body, but the soul is never born and never dies, so if there is no birth how there can be new soul.” (Letter to Jagadisa dasa 7/9/1970)

Srila Prabhupada – “Regarding your questions concerning the spirit souls falling into Maya’s influence, it is not that those who have developed a passive relationship with Krsna are more likely to fall into nescient activities. 

Usually anyone who has developed his relationship with Krsna does not fall down in any circumstance, but because the independence is always there, the soul may fall down from any position or any relationship by misusing his independence.” (Letter to Jagadisa dasa 02/27/1970)

Srila Prabhupada – “But his relationship with Krsna is never lost, simply forgotten by the influence of maya social, it maybe regained or revived by the process of hearing the Holy Name of Krsna and then the devotee engages himself in the service of the Lord which is his original constitutional position. The relationship of the living entity with Krsna is eternal as both Krsna and the living entity are eternal; the process is one of revival only, nothing new.” (Letter to Jagadisa dasa 02/27/1970)

Krsna (God) is more inclined to help those who first do everything they can to help themselves find a spiritual master to teach them spiritual life.

If one is honest with themselves, Krsna sends the Guru (spiritual teacher) who will guide them out of the material creation and return back home, back to Godhead to be with Krsna.

Only then will Krsna help you when He sees you are trying your very hardest to do everything you can to help yourself, only then will Krsna send you a spiritual teacher. 

Srila Prabhupada – “In all the śāstras [scriptures] the guru is described to be as good as God, but the guru never says, ‘I am God.’ The disciple’s duty is to offer respect to the guru just as he offers respect to God, but the guru never thinks, ‘My disciples are offering me the same respect they offer to God; therefore, I have become God.’ As soon as he thinks like this, he becomes a dog.” (From the Book, Science of realization)

Real loving exchanges are voluntary and reciprocal, it is never a one-way street where Krsna does everything for you.

Surrender to Krsna's pure devotees does not mean you lose your free will, independence and individuality to be qualified to enter the spiritual world, no, such bogus surrender is impersonalism.  

The marginal living entity (jiva-soul) has always had freedom (free will) therefore, there is no question of the marginal living entity ever not having free will because free will in Vaikuntha and Goloka-Vrindavana is perpetually part and parcel of all marginal living entities (jiva-souls) make up.

The marginal living entities (jiva-souls) originate from Goloka-Vrindavana and not the Impersonal Brahman as Prabhupada teaches.

Originally all jiva-souls are nitya-siddha because they all come from Goloka-Vrindavana, only when they enter the material creation and the impersonal brahman do they then become nitya-baddha.

Therefore nitya-siddha can become a nitya-baddhas and nitya-baddhas can AGAIN become nitya-siddha.

The following Conversation took place in Melbourne, Australia June 25, 1974 between Srila Prabhupada and his disciples.

Devotee – “When we are in the spiritual sky and serving Krsna, we have a perfect relationship with Krsna, what causes us to fall down in the material world, because we’re already serving Krsna?”

Srila Prabhupada – “Because you desire to fall down. Here it is explained that “Don’t fall down.”

Devotee – “Srila Prabhupada, I can’t understand why we should have an impure desire when we are already serving.”

Srila Prabhupada – “Because you have got little freedom. Why one is not coming here and going to the liquor shop? It is desire.”

Devotee – “In the Srimad-Bhagavatam, it says that Krsna did not want us to come to this material world. If Krsna did not want us to come, why are we here?”

Srila Prabhupada – "Yes, you forced Krsna to allow you to come. Just like sometimes a child forces his father. Father says, “My dear son, do not do this. Do not go there.” But he insists, “Oh, I must go. I must go.” “All right, you go at your risk. That’s all. And you suffer. What can be done?” Because you are Son of God you have got independence, full independence, almighty—therefore you have acquired the quality of your father. You have got little independence. So God does not interfere with your little independence. If you persist that “I must go and enjoy independently,” so God says, “All right, you can go.” This is the position. You have to take sanction. That is a fact. But when you persist, God sanctions. And you come and enjoy.” (Melb, Australia June 25, 1974)

Question - Is there a place in the spiritual world from where we can never fall down from?"

Answer - No, it is not based on a place where you can never fall down from that keeps you in Vaikuntha, it does not work that way because of free will, which means there is always choice to leave Vaikuntha at any moment. 

If you were forced to stay there then how can there be love? The choice to leave or stay must always be with the jiva-souls too.

So many cannot understand what free will really means, they sentimentally claim- “Not even the leaves fall from Vaikuntha.”

It is nonsense to claim the jiva-souls can ever again fall down from Vaikuntha and Goloka-Vrindavana because they each have their own free will and can make their own decisions no matter what Kṛṣṇa promises.

Remaining in Vaikuntha and Goloka-Vrindavana eternally is based on what the jiva-soul's want to do as a unique individual, it is also their choice to say or go, not just Krsnas as explained above, otherwise there is no meaning to having free will.

If Krsna forced His will on the jiva-souls then He destroys their independence, free will and ability to voluntarily express themselves in their own unique way, allowing themselves to choose where they want to be even if returning to the material creation.

In other words, the jiva-souls also have a choice to become a servant of the Lord or can reject Him if they want, even in Vaikuntha and Goloka Vrindavana, only sentimental fools polluted by impersonalism cannot understand this.

The jiva-souls never lose their unique ability of free will and independent self expression, where one is personally always aware they can choose how to selflessly serve Krsna in their own unique way as the loving servant of the servant of Krsna.

The fact that one does not again fall from Krsna's personal Kingdom is the jiva-soul's responsibility too and not just only Krsnas.

It is the jiva-soul's choice as well, it is their free will to choose and no one else can choose for them including Krsna.

However, 90% of all jiva-souls do not fall down from Vaikuntha or Goloka Vrindavana because they choose not to, but even that can change because of free will.

That choice to stay in Vaikuntha or leave is always with the marginal living entities or jiva-souls.

The jiva-souls or marginal living entities have 78.125% of Krsna's quantities or 50 of Krsna's 64 attributes which puts them in the realm of having independence, identity, personality, individuality and the ability to choose. This means the jiva-souls have the ability to agree or not agree with Krsna. 

Their individuality allows the jiva-souls the right to choose Krsna or choose to be separate from Krsna, this is the meaning of free will.

Remember, Maya and the material energy do not exist in Vaikuntha or Goloka-Vrindavana, so Maya is unknown to the jiva-souls in the spiritual worlds.

However, free will and independence allows the jiva-souls to experience a unique sense of individuality with the ability to express oneself in their own way. 

All these qualities are the constitutional makeup of each jiva-soul in Vaikuntha and Goloka Vrindavana. 

And if all those abilities are taken away, then the jiva-souls lose the ability to give and accept love and become no better than dead stone.

Srila Prabhupada – “If you have no free will, then you are a stone. The stone has no free will. Do you want to be stone? Then, you must have free will! But don't misuse your free will. But don't try to become stone either. That is not life.” (Aug 5, 1976, New Mayapur France)

Srila Prabhupada – “Because you are Son of God you have got independence, full independence, almighty, therefore you have acquired the quality of your father. You have got little independence. So God does not interfere with your little independence.” (Melbourne, Australia June 25, 1974)

No one forces the jiva-souls to stay in Vaikuntha or Goloka-Vrindavana, that choice 

For loving exchanges to truly exist with the jiva-soul, they must have the right to express themselves and choose to leave Vaikuntha or Goloka Vrindavana at anytime, therefore returning there is not necessarily permanent.

Syamasundara – “But can we predict that the process (returning back home back to Godhead) will be permanent? Can we predict that? Just like many prisoners.” 

Srila Prabhupada – “Yes, otherwise there is no meaning of independence and free will. Independence means you can do this, you can do that. “All right. Whatever you like.”

Devotee - “Then he is so many times falling down, again and again, so will he eventually permanently come back?”

Srila Prabhupada – “No, there is no question of permanent because he has got independence, he can misuse his independence, he can fall down. That's why when a man is released from the prison house, that does not mean permanently because he can come back again, the general law is not to come back. but if he likes, he can come back, otherwise what is the meaning of independence? Just like one becomes free from the prison house, naturally he should not go there again.” (Discussions with Syamasundara > Henri Bergson)

The jiva-souls have 78.125% of Krsna's qualities [50 of His 64 attributes], they are minor expansions of Krsna endowed with individuality that allows them to experience an independent personal sense of self separate from Krsna but still dependent on Him. 

This allows the jiva-souls to make their own decisions and choices. Therefore, Krsna does not interfere with the jiva-soul's free will because it is part of the eternal constitution of all jiva-souls.

Krsna never at any point did not give freedom or free will to the marginal living entities (jiva-soul) because they have always had free will in Vaikuntha and Goloka-Vrindavana without beginning or end. 

Free will allows the jiva-souls to experience individuality, loving reciprocation, independent service, and be responsible for their actions.

This however does not means all jiva-soul's are independent from Krsna's control of all things, that is not possible. 

At all time the jiva-souls are always dependent on Krsna or His expansions, even as independent individuals because Krsna is the Supreme Personality of Godhead and cause of all causes.

Therefore the jiva-souls always remain independent living entities, but always simultaneously depend on Krsna and His expansions in both the spiritual worlds and material worlds.

The jiva-souls are never fully independent because Krsna owns everything.

So even though the jiva-souls are an expansion of Krsna, the jiva-souls are not one with Krsna in personality. 

Both are independent with their own unique personality.

The individual jiva-souls are not one with Krsna but are independent thinking living entities with their own sense of self and personality that makes them one in purpose. 

Lord Caitanya Mahaprabhu is the manifestation of Radha and Krsna in one Body where both experience each other's love for each other. 

In fact, Krsna, Balarama, Radharani and Lord Caitanya are all the one personality, are all Visnu-tattvas originating from Krsna.

The claim that once reaching Vaikuntha or Goloka-Vrindavana the jiva-souls can never again fall down, is not exactly correct. 

To claim those who enter Vaikuntha or Goloka-Vrindavana will never again fall down to the material creation is only true for those who choose not to fall down.

In other words, if the jiva-soul wants to leave they certainly can. 

Going to the material worlds is ultimately the jiva-soul's choice and Krsna does not interfere, even though He has promised there is no return to the material creation once entering the spiritual atmosphere. 

This is simple because they can even reject Krsna's promise. 

The fact, there is return if the jiva-souls wants to return to the material creation Prabhupada tells us, it is their choice. 

Acyutananda – “But in the Bhagavad Gita it says, "Once coming back to the spiritual abodes, the jiva-soul never returns to the material world, he can return?”

Srila Prabhupada – “If he likes he can return.”

Guru-kripa – “How is it that one can become envious of Krsna?”

Srila Prabhupada – “You have got little independence, you can violate. Because you are part and parcel of God, God has got full independence, but you have got little independence, proportionately, because you are part and parcel, if he likes, he can return. That independence has to be accepted, little independence. We can misuse that. Krsna-bahirmukha haïä bhoga väïchä kare. That misuse is the cause of our falldown.” (Conversation, Mayapur, Feb 19, 1976)

So clearly those who believe no one can ever fall down from Vaikuntha have not understood the variety of living entities in Vaikuntha of whom the jiva-souls are just one and Prabhupada's comments here.

As said above, only a very small minority of jiva-souls (less than 10%)  choose to leave but not in the category of Visnu-tattvas who can never fall down because they are Krsna Himself playing another role in His own pastimes.

Many have not understood there are many different categories of living entities in Vrindavana who never fall down, such as the many Visnu-tattva personalities.

And for over 90% of jiva-souls, they also never fall down because they choose not to fall down.

Devotee – “Well, I believe you once said that once a conditioned soul becomes perfected and gets out of the material world and he goes to Krsnaloka (Goloka-Vrindavana) there’s no possibility of falling down again?”

Srila Prabhupada – “No, there is possibility, but he does not come IF he in intelligent. Just like after putting your hand in the fire, you never put it in again if you are really intelligent. So those who are going back to Godhead, they become intelligent.” (CC, Adi-lila 7.108-San Francisco, Feb 18, 1967)

Free will is eternal in the spiritual worlds and without having the choice to either forget or remember Krsna, then we would have no independent personality separate from Krsna's Personality and no ability to voluntarily offer love, we would be like dead stone. 

The eternal constitution and original position of the marginal living entities (jiva-souls) is fully explained by Krsna disguised as a brahmana as follows- 

The Brāhmaṇa said – “My dear friend, even though you cannot immediately recognize Me, can't you remember that in the past you had a very intimate friend? Unfortunately, you gave up My company and accepted a position as enjoyer of this material world.” (4th Canto Ch 28 text 53)

Srila Prabhupada – “So everyone can know that independence means one can use it properly, one can misuse it. That is independence. If you make it one way only, that you cannot become fall down, that is not independence. That is force. Therefore Krsna says, yathecchasi tathä kuru. “Now you do whatever you like.” (Los Angeles, June 23, 1975)..^^^..