The word "Vaikuntha" means "without anxiety" therefore how could there be demons on the Vaikuntha planets or in Goloka-Vrindavana?

Furthermore, how could the gopis ever feel separation from Kṛṣṇa there? After all Krsna NEVER leaves Goloka Vrindavana.

Jayatīrtha dasa - "If the original Kṛṣṇa is always in Vṛndāvana, then why do the gopīs and Rādhārāṇī feel separation from Him?"

Srila Prabhupada - "That is here, in this material world. In the spiritual world Kṛṣṇa does not leave."

Jayatīrtha dasa - "Oh."

Srila Prabhupāda - "And even in the material world, Kṛṣṇa superficially has gone to Mathurā, but He has captured the heart of the gopīs. So He is not leaving. Gopīs are enjoying Kṛṣṇa by separation. That is Caitanya Mahāprabhu's feeling, how He is appreciating Kṛṣṇa by separation." (Morning Walk, July 17, 1975, San Francisco)

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

Srila Prabhupada - "The spirit soul is NOT formless; it has got form, the spirit soul always has form and is expressed as hands, legs, heads, everything. But with our material eyes at the present, our gross eyes, we cannot see these facts; therefore we foolishly believe the jiva-souls have no form." (Lecture BG, Ch 2 Text 14, Mexico, Feb 14, 1975)

The jiva-souls (marginal living entities) are eternal PERSONS, as a spiritual bodily form like Krsna's Body, whose perpetual permanent natural home is the spiritual world.

God (Krsna) is not ONLY an all-pervading consciousness who is even in the atom, no, Krsna the Supreme Personality of Godhead and cause of all causes, is also simultaneously an individual "PERSON" as an eternal spiritual bodily Form, who's Bodily rays ARE the Brahmajyoti.

Srila Prabhupada - "Each "person" (jiva-soul) is eternal. Lord Krsna says that He existed as a person before the creation (agre) and will also exist after the annihilation, the Lord is a "person" eternally." (SB, Canto, 6 Ch 4 text 47, Purport)

Devotee - "If the spirit soul (jiva-soul) is nonmaterial and has form, what is that form?"

Srila Prabhupāda - "There is form, just like this body is compared with the dress. Now, just like in your present material form you have got hand; therefore your coat has got hand, you have got leg; therefore your pant has got leg. Therefore, it is to be assumed that the spirit soul has got form, and it has developed into hands, legs, heads, everything. It is not formless; it has got form. But with our material eyes at the present, gross eyes, we cannot find it; therefore we say it has no form." (Lecture BG, Ch 2 text 14 Mexico, Feb 14, 1975)

Devotee - "Is the original body of the spirit 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 dasa - "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, but they are more covered in the material world, 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 soul."

Hari-sauri dasa- "They are covered in the spiritual world?"

Srila Prabhupada - "Not in the spiritual world, there the form one chooses is voluntary, some devotee want to serve Krsna as a flower; they become flower there. If I want to be a flower I shall lie down at the lotus feet of Krsna, he becomes flower, voluntarily, and he can change his, from flower to human body. 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 Ch 1 Text 1-4 Melb, May 20, 1975)

Devotee - "Śrīla Prabhupāda, you state that spirit soul has form."

Srila Prabhupāda - "Yes."

Devotee - "Otherwise, how is the material body grown to accommodate the spirit soul? Just like a shirt has no form, but when it's put on the body, it takes the shapes of the body. Does that mean that the jiva-soul has the shape of the body that is accommodating it?"

Srila Prabhupāda - "Yes, you have got body, shape, very minute shape, that we cannot see, we cannot measure. Therefore in the Bhagavad-gītā it is said, anumeyam. You cannot measure. What is that word used? Aprameyam. Aprameyam, you cannot measure but it has a form. What is the length and breadth of that form, that is not in your power to understand, not materially. If you have got spiritual power then you can measure it. And that measurement is also given in the śāstra. What is that? One ten-thousandth part of the tip of the hair. Hair is a very small point. And divide it into ten thousand parts. That one part is the measure, magnitude of the soul." (Lecture SB, Canto 1 Ch 16 text 24 Hawaii, Jan 20, 1974)

Hayagrīva dasa - "There is no difference between God's form and His spiritual self?"

Srila Prabhupāda - "Yes, as in the material world any form-man or beast or anyone—in the outward, external covering is matter, but within the matter there is the soul. The soul has form and God has form. That is real form. And the material form is simply shirting and coating over the spiritual body." 

Hayagrīva dasa - "Thomas Aquinas considered that matter was necessary to give the jiva-soul form?"

Srila Prabhupāda - "No, no, he has got his original form."

Hayagrīva dasa - "Original form?"

Srila Prabhupāda - "Yes."

Hayagrīva dasa - "Which is the form of the body."

Srila Prabhupāda - "Original form, that is the form of the spirit (jiva-soul)."

Hayagrīva dasa - "Of the spirit."

Srila Prabhupāda - "Yes, and the form of the body takes place on account of the form of the spirit (jiva-soul). This is very nice example. The cloth has no form, but when it is cut according to the form of the gentleman, it takes a form. Similarly, matter has no form. When it is coated on the spiritual form of the soul, it takes the form. This is very easy to understand." (Philosophy Discussion with Srila Prabhupāda on Thomas Aquinas beliefs).^^.