The position of Radharani, Her sakti and Krsna's internal energy or potency.

Srila Prabhupāda  - "Without energy, there is no meaning to the energetic, and without the energetic there is no meaning to the energy. 

Similarly, without Radha there is no meaning to Krsna and without Krsna there is no meaning to Radha. 

Because of this, the Vaisnava philosophy first of all pays obeisances to and worships the internal pleasure potency of the Supreme Lord. Thus the Lord and His potency are always referred to as Radha-Krsna. 

Similarly those who worship Narayana first utter the name of Laksmi, as Laksmi-Narayana. 

Similarly those who worship Lord Rama first utter the name of Sita. In any case — Sita-Rama, Radha-Krsna, Laksmi-Narayana– the potency always comes first.” (Caitanya-caritamrta, Introduction)

Srila Prabhupāda  - “Lord Krsna’s Pleasure Potency is called Hladini, so this spiritual energy of Krsna’s pleasure potency, Hladini, is Srimati Radharani Who is always increasing the transcendental pleasure of Krsna by Her super-excellent loving devotional service.” (Letter, March 29, 1970)

Srila Prabhupada - “Krsna is the energetic, and Radharani is the energy. Just like energy and energetic, you cannot separate. Fire and the heat you cannot separate. Wherever there is fire there is heat, and wherever there is heat there is fire. Similarly, wherever there is Krsna there is Radha. And wherever there is Radha there is Krsna. They are inseparable.” (Lecture, Aug 30, 1968)

Srimati Radharani's position is always difficult to understand.

All living entities are sakti-tattva, including all other energies (matter) of Krsna however, there are different categories. To start with, basically there are only two types of living entities, Visnu-tattva, who has 60 of Krsna's 64 qualities, which is 93.75%, and jiva-tattva (jiva-souls) who have 50 of Krsna's 64 qualities, which is 78.125%  

Srila Prabhupada – “In the Padma Purana, wherein it is said that there are two kinds of spiritual entities; one is called the jiva (jiva-tattva or jiva-souls), and the other is called the Supreme Lord (Visnu-tattva)." (87th Ch of Krsna Book, Prayers by the Personified Vedas)

There is also Siva-tattva however, he is neither Visnu-tattva (God) or jiva-tattva (jiva-soul). He is mysteriously in the middle of the two. Siva has 55 of Krsna's 64 qualities which is 84.375% of Krsna's attributes.

Srimati Radharani's position is always difficult to understand because She is in her own unique category of sakti who represents Krsna's internal energy. 

Srimati Radharani is the internal energy, we are marginal energy (jiva-souls)

Srila Prabhupada - "Regarding your question about our relationship with Srimati Radharani, She is the internal energy, we are marginal energy. Marginal means sometimes internal, sometimes external. When we are under the internal energy, that is our normal life, and when we are under the external energy, that is our abnormal life. Therefore, we are called marginal energy; we can be either this way or that way. But being qualitatively one with the purusa, our tendency is to remain in the internal energy. Being in the external energy is our artificial attempt." (Letter to Lilavati - Allston, Mass 25 April, 1969)

Radharani is NOT jiva-tattva (jiva-soul) because She is non-different than Kṛṣṇa, therefore, going by the above quote from Padma Purāṇa, Radarani is Visnu-tattva.

Radharani is no different than Kṛṣṇa, created by Him for the purpose to experience loving reciprocal exchanges and emotions with a women.

In vaniquotes it is explained that Radharani represents Krsna's internal energy or potency and is in the combination called "Sakti-Visnu-tattva." 

These three words "Sakti, Visnu, tattva" refers to Radharani being simultaneously Krsna's internal energy (sakti) and Krsna's direct expansion (Visnu-tattva). And furthermore,  when Krsna and Radharani combine in the one Body, that Body is Lord Caitanya Mahaprabhu.

Srila Prabhupada - "Tattva is manifested in different ways: Viṣṇu-tattva, Viṣṇu-śakti-tattva, jīva-tattva, like that." (Lecture on SB 6.2.7 - Vrndavana, Sept 10, 1975)

As said above, "Sakti" means the different categories of "energies" of Krsna, living and non-living as Srila Prabhupada explains. 

Srila Prabhupāda - "Sakti means “energy.” There are many types of energies of the Supreme Lord, and all of them are auspicious. Brahmā, Viṣṇu and Maheśvara are called guṇa-avatāras, or incarnations of material qualities. 

In the material world we compare these different incarnations from different angles of vision, but since all of them are expansions of the supreme auspicious, all of them are auspicious, although sometimes we consider one quality of nature to be higher or lower than another. The mode of ignorance, or tamo-guṇa, is considered very much lower than the others, but in the higher sense it is also auspicious. The example may be given herein that the government has both an educational department and criminal department. 

An outsider may consider the criminal department inauspicious, but from the government’s point of view it is as important as the education department, and therefore the government finances both departments equally, without discrimination." (SB Canto 4 Ch 6 text 43 Purport)

Srila Prabhupāda  - “The beauty of Srimati Radharani is described as follows: ‘Her eyes defeat the attractive features of the eyes of the cakori bird. When one sees the face of Radharani, he immediately hates the beauty of the moon. Her bodily complexion defeats the beauty of gold. Thus, let us all look upon the transcendental beauty of Srimati Radharani." (Nectar of Devotion, Ch 44)

Srila Prabhupāda  - “In Vrindavana all the pure devotees pray for the mercy of Srimati Radharani, the pleasure potency of Lord Krsna. 

Srimati Radharani is a tenderhearted feminine counterpart of the supreme whole, resembling the perfectional stage of the worldly feminine nature. Therefore, the mercy of Radharani is available very readily to the sincere devotees, and once She recommends such a devotee to Lord Krsna, the Lord at once accepts the devotee’s admittance into His association. 

The conclusion is, therefore, that one should be more serious about seeking the mercy of the devotee than that of the Lord directly, and by one’s doing so (by the good will of the devotee) the natural attraction for the service of the Lord will be revived.” (SB Canto 2 Ch 3l text 23, Purport)

Srila Prabhupāda  - “You’ll find in Vrindavan, if you go to Vrindavan, everyone is worshiping Radharani. Rani means queen. They are always speaking, ‘Jaya Radhe!’ Radharani. All the devotees in Vrindavan, they are worshiper of Radharani. 

Hari-niskuta-vrnda-vipinese. Vrsabhanu-dadhi-nava-sasi-lekhe. 

And She appeared as the daughter of King Vrsabhanu, and Her companion, Lalita-sakhi and Visakha-sakhi, and the devotees.

So on behalf of the pure devotees of Krsna, Rupa Gosvami is praying, karunam kuru mayi karuna-bharite. 

‘Oh, my worshipable Radharani, You are full of mercy. So I am begging of Your mercy because You are so merciful, very easily You offer, bestow Your mercy. So I am begging Your mercy." (Lecture, Aug 30, 1968)

Srila Prabhupāda  - “There is a supreme symptom of ecstatic love which is called maha-bhava. This mahabhava expression was possible only in Radharani, but later on when Sri Krsna Caitanya appeared to feel the mode of love of Radharani, He also expressed all the symptoms of maha-bhava. 

Sri Rupa Gosvami says in this connection that when the symptoms of ecstatic love become the most bright, that stage is accepted as mahabhava.” (Nectar of Devotion, Ch 28)

Srila Prabhupāda  - “Yes, you are certainly right when you say Radharani cooks prasadam for Lord Krsna. Whenever He returns in the evening from herding cows with His cowherd boy friends, Radharani has a nice preparation waiting for Lord Krsna.” (Letter, Aug 5, 1970)

Srila Prabhupāda  - “Krsna likes Radharani. Therefore all the gopis, they are trying to push Radharani to Krsna. ‘Krsna likes this gopi. All right, push Her.’ That is Krsna consciousness. 

To satisfy the senses of Krsna, not to satisfy my senses. That is bhakti. That is called prema, love for Krsna. ‘Ah, Krsna likes this. I must give Him this." (Perfect Questions, Perfect Answers, Ch 6)

Srila Prabhupāda  - “The beauty of Srimati Radharani’s eyes forcibly devours the beauty of newly grown blue lotus flowers, and the beauty of Her face surpasses that of an entire forest of fully blossomed lotuses. Her bodily luster seems to place even gold into a painful situation. Thus the wonderful, unprecedented beauty of Srimati Radharani is awakening in Vrindavana.” (CC Antya 1.169)

Srila Prabhupada - “Sri Krsna continued: ‘All the inhabitants of Vrindavana-dhama — My mother, father, cowherd boy friends and everything else — are like My life and soul. And among all the inhabitants of Vrindavana, the gopis are My very life and soul. Among the gopis, You, Srimati Radharani, are the chief. Therefore You are the very life of My life." (CC Madhya 13.150)

Srila Prabhupada - “In Radharani is found the science of ujjala, or the brightest jewel of love of God.” (Krsna Book, Ch 47)

Srila Prabhupada - “Among all the gopis, Srimati Radharani is the most exalted. She is the most beautiful, the most qualified and, above all, the greatest lover of Krishna.” (CC Adi 4.214, Purport)

Srila Prabhupada - “Radharani is the best, topmost servitor of Krsna, and the printing machine is the biggest medium at the present moment for serving Krsna. Therefore it is really a representative of Srimati Radharani.” (Letter, Aug 13, 1969)

Srila Prabhupada - "Krsna, everyone is trying to love Krsna, but Krsna is trying to love somebody. Now how great She is. Just try to understand. Everyone, the whole world, the whole universe, all living entities, they are trying to love Krsna, krsna-prema. 

Lord Caitanya describes, prema-pumartho mahan. And Rupa Gosvami described that ‘You are distributing krsna-prema.’ So krsna-prema is so valuable, but Krsna is after Radharani. Just see how Radharani is great. 

Just try to understand the greatness of Radharani. Therefore She is so great, and we have to offer our respect.” (Lecture, Aug 30, 1968)

Srila Prabhupada - “Srila Raghunatha dasa Gosvami offers his respectful obeisances to Srimati Radharani, taking a straw in his mouth. Indeed, he prays, ‘O Gandharvika, Srimati Radharani, just as Lord Krsna never rejects a surrendered soul, please don’t reject me." (CC Madhya 8.166, Purport)

Srila Prabhupada - “Radharani can deliver Krsna. She is so great a devotee, the emblem of maha-bhagavata. Even Krsna cannot understand the quality of Radharani’s devotion. Although Krsna says vedaham samatitani — ‘I know everything’ — He fails to understand Radharani. Radharani is so great.” (Lecture, Sept 18, 1969)

Srila Prabhupada - “I am very much indebted to my father, for he took care of me in such a way that I became perfectly Krsna conscious. My father used to receive many saintly persons at our home, and to every one of them he used to say, ‘Kindly bless my son so that he may become a servant of Radharani.’ That was his only ambition.” (Conversation, Oct, 1973)*×*.