It is accepted by the majority of the members of the Vaisnava community that once having attained the spiritual world one cannot fall down. Numerous sastric texts (and commentaries) support this, such as: Bhagavad-gita 4.9, 8.15, 8.16, 13.24, 15.4, 15.6, 8.22, purport [of A.C. Bhaktivedanta Swami Prabhupada], and Srimad-Bhagavatam 2.2.31, 10.6.40, 3.16.12, purp., 3.25.29, purp., 7.1.34, purp. for example. We substantiate, by pertinent quotes, in the following section that nitya-siddha devotees, eternal residents who are already in the spiritual world, also never fall down from Vaikuntha or Goloka.
Sastric texts:
A pure devotee of the Lord can never forget those lotus feet in any circumstance. He will not give up his shelter at the lotus feet of the Lord for a single moment-indeed, not for half a moment-even in exchange of the benediction of ruling and enjoying the opulence of the entire universe. (Bhag. 11.2.53, text)
The living entities [jivas] are divided into two categories. Some are eternally liberated, and others are eternally conditioned. Those who are eternally liberated are always awake to Krsna consciousness, and they render transcendental loving service at the feet of Lord Krsna. They are to be considered eternal associates of Krsna, and they are eternally enjoying the transcendental bliss of serving Krsna. (Cc. Madhya-lila 22.10-11, text)
In the spiritual sky there are spiritual planets known as Vaikunthas, which are the residence of the Supreme Personality of Godhead and His pure devotees) (Bhag. 3.15.13, text.)
. . . and in the spiritual world every living entity is called infallible. (Bg. 15.16, text)
Srila Vrndavana dasa Thakura:
Therefore there is no birth or death for the Vaisnavas [the eternal associates]. They descend to the material world with the Lord and return to His abode with Him. The Vaisnava is never bound by karma and thus does not take birth in the material world. (Caitanya-Bhagavata Antya-lila 10.172)
Srila Rupa Gosvami:
Even the associates of the Lord are described as having eternal forms. (Laghu-bhag. 1.143)
The samprapta-siddhas are those who have become perfect by performing bhakti and nitya-siddhas are those who have never been conditioned and thus are eternally siddhas. (Brs. 2.1.281, text)
The nitya-siddha devotees love Krsna millions of times more than their own selves. They all have eternal, blissful qualities just like Lord Krsna. (Brs. 2.1.290, text)
Srila Jiva Gosvami:
The third of ten characteristics of Vaikuntha listed by Srila Jiva Gosvami in Bhagavat-sandarbha, text 61, is that anyone who has attained Vaikuntha does not fall. Srila Jiva Gosvami also provides numerous examples and quotes as proof of this fact.
Srila Baladeva Vidyabhusana:
Srila Baladeva Vidyabhusana writes in Govinda-bhasya, "One cannot even imagine that the Supreme Lord Hari would ever desire that the liberated souls fall down, nor would the liberated souls ever desire to leave the Lord." He further states that this is because of their extreme mutual love and cites four verses as evidence (Bg. 7.17, Bhag. 9.4.68, 9.4.65 and 2.8.6).
Srila Bhaktivinode Thakura:
Mahavisnu, the incarnation of Sankarsana, establishing Himself in the jiva-sakti as Paramatma, reveals the jiva-souls of the mundane world. These jivas are susceptible to the influence of maya. Till by dint of God's grace they get shelter under the Hladini (bliss-giving) element of the cit-sakti, they are liable to be overcome by maya. As such, the conclusion is that it is the jiva-sakti that begets the jivas, and not the cit-sakti. (Jaiva-Dharma, p. 216)
. . . Gradually they reach the transcendental abode of the Lord and attain the exact same status as His eternal associates. (Jaiva Dharma, p. 229)
Srila Bhaktisiddhanta Sarasvati Thakura:
Jivas are of two kinds. 1) Nitya-mukta (eternally free) 2) Nitya-baddha (eternally enslaved). Free jivas are never enslaved. They are ever serving the Supreme God. (Vaisnavism Real and Apparent, Lecture, Bhaktisiddanta S T )
Srila A. C. Bhaktivedanta Swami Prabhupada:
The living entities are parts and parcels of the Lord. They are of two varieties, namely nitya-mukta and nitya-baddha. The nitya-muktas are eternally liberated souls, and they are eternally engaged in the reciprocation of transcendental loving service with the Lord in His eternal abode beyond the manifested mundane creations. (Bhag.1.10.22, purp.)
. . . the planets in the spiritual sky . . . are in fact transcendental to the material modes . . . The conception of spiritual bliss (Brahmananda) is fully present in those planets . . . and free from all kinds of inebriates experienced in the material world . . . The inhabitants of those planets are liberated from birth, death, old age and diseases and have full knowledge of everything; they are all godly and free from all sorts of material hankerings. They have nothing to do there except to render transcendental loving service to the Supreme Lord . . . The Lord and His eternal servitors in the transcendental kingdom all have eternal forms which are auspicious, infallible, spiritual and eternally youthful. In the words, there is no birth, death, old age and disease. That eternal land is full of transcendental enjoyment and full of beauty and bliss. This very fact is also corroborated in this verse of Srimad-Bhagavatam, and the transcendental nature is described as amrta. As described in the Vedas, utamrtatvasyesanah: the Supreme Lord is the Lord of immortality, or in other words, the Lord is immortal, and because He is the Lord of immortality He can award immortality to His devotees. In the Bhagavad-gita (8.16) the Lord also assures that whoever may go to His abode of immortality shall never return to this mortal land of threefold miseries . . . In the material world there is always anxiety or fearfulness in the hearts of all living entities, but the Lord, being Himself the supreme fearless, also awards the same quality of fearlessness to His pure devotees. Mundane existence is itself a kind of fear because in all mundane bodies the effects of birth, death, old age and disease always keep a living being compact in fear. In the mundane world, there is always the influence of time, which changes things from one stage to another, and the living entity originally being avikara, or unchangeable, suffers a great deal on account of changes due to the influence of time.
The changing effects of eternal time are conspicuously absent in the immortal kingdom of God, which should therefore be understood to have no influence of time and therefore no fear whatsoever. (Bhag.2.6.18, purp.)
The nitya-siddha devotees never fall down to the region of the material atmosphere even though they sometimes come into the material plane to execute the mission of the Lord. (Bhag. 3.3.26, purp.)
A pure living entity in his original spiritual existence is fully conscious of his constitutional position as an eternal servitor of the Lord. All souls who are situated in such pure consciousness are liberated, and therefore they eternally live in bliss and knowledge in the various Vaikuntha planets in the spiritual sky. When the material creation is manifested, it is not meant for them. The eternally liberated souls are called nitya-muktas, and they have nothing to do with the material creation. The material creation is meant for rebellious souls who are not prepared to accept subordination under the Supreme Lord. (Bhag. 3.5.29, purp.)
. . . a devotee in the transcendental abode of the Lord never falls. (Bhag. 3.15.48, purp.)
After finishing their mock fighting, both the devotee and the Lord are again associated in the spiritual planets. That is very explicitly explained here. The conclusion is that no one falls from the spiritual world or Vaikuntha planet, for it is the eternal abode. (Bhag. 3.16.26, purp.)
The inhabitants of Vaikuntha never return to the material world. (Bhag. 3.16.27, purp.)
A devotee once accepted by the Lord, can never fall down. That is the conclusion of this incident. [Jaya and Vijaya] (Bhag. 3.16.29, purp.)
The word kuta-stha, meaning "without change," is also very significant. There are two kinds of living entities-nitya-mukta and nitya-baddha. A nitya-mukta never forgets his position as the eternal servant of the Supreme Personality of Godhead. One who does not forget this position and knows that he is part and parcel of the Supreme Lord is nitya-mukta. Such a nitya-mukta living entity represents the Supersoul as His expansion. As stated in the Vedas, nityo nityanam. Thus the nitya-mukta living entity knows that he is an expansion of the supreme nitya, or the eternal Supreme Personality of Godhead. (Bhag. 4.16.19, purp.)
Some living entities are conditioned, and others are eternally free. The eternally free living entities are called nitya-mukta, for they never come in contact with the material energy. However, some living entities are conditioned in this material world, and thus they think themselves separated from the Supreme Lord. (Bhag. 4.24.61, purp.)
All the residents of Vaikunthaloka know perfectly well that their master is Narayana, or Krsna, and that they are all His servants. They are all self-realized souls who are nitya-mukta, everlastingly liberated. Although they could conceivably declare themselves Narayana or Visnu, they never do so; they always remain Krsna conscious and serve the Lord faithfully. Such is the atmosphere of Vaikunthaloka. (Bhag. 6.1.34-6, purp.)
From authoritative sources it can be discerned that associates of Lord Visnu who descend from Vaikuntha do not actually fall. They come with the purpose of fulfilling the desire of the Lord, and their descent to this material world is comparable to that of the Lord. The Lord comes to this material world through the agency of His internal potency, and similarly, when a devotee or associate of the Lord descends to this material world, he does so through the action of the spiritual energy. Any pastime conducted by the Supreme Personality of Godhead is an arrangement by yoga-maya, not maha-maya. Therefore it is to understood that when Jaya and Vijaya descended to this material world, they came because there was something to be done for the Supreme Personality of Godhead. Otherwise it is a fact that no one falls from Vaikuntha. (Bhag. 7.1.35, purp.)
One who is not materially infected and who does not forget Krsna as his master is called nitya-mukta. In other words, one who is eternally liberated from material contamination is called nitya-mukta. From time immemorial the nitya-mukta living entity has always been a devotee of Krsna, and his only attempt has been to serve Krsna. Thus he never forgets his eternal servitorship to Krsna. (Cc. Madhya-lila 20.118, purp.)
Srila Prabhupada confirms his agreement with Srila Bhaktivinoda Thakura.
An explanation of verses 8 through 15 is given by Srila Bhaktivinoda Thakura in his Amrta-pravaha-bhasya . . . The living entities are divided into two categoriesthe eternally liberated and eternally conditioned. Those who are ever-liberated never come in contact with maya, the external energy. The ever-conditioned are always under the clutches of the external energy . . . The nitya-baddhas are always conditioned by the external energy, and the nitya-muktas never come in contact with the external energy. Sometimes an ever-liberated personal associate of the Supreme Personality of Godhead descends into this universe just as the Lord descends. Although working for the liberation of conditioned souls, the messenger of the Supreme Lord remains untouched by the material energy. Generally ever-liberated personalities live in the spiritual world as associates of Lord Krsna, and they are known as krsna-parsada, associates of the Lord. Their only business is enjoying Lord Krsna's company, and even though such eternally liberated persons come within this material world to serve the Lord's purpose, they enjoy Lord Krsna's company without stoppage . . . The ever-conditioned soul, provoked by lusty desires to enjoy the material world, is subjected to transmigrate from one body to another . . . If by chance he meets a saintly person who works on Krsna's behalf to deliver conditioned souls, and if he agrees to abide by his order, he can gradually approach the Supreme Personality of Godhead, Krsna. (Cc Madhya-lila 22.14-15, purp.)
The third-class person in Krsna consciousness may fall down, but when one is in the second class he does not fall down, and for the first-class person in Krsna consciousness there is no chance of falling down. (Bg. 9.3, purport)
The pure devotee has no actual chance to fall down, because the Supreme Godhead personally takes care of His pure devotees. (Bg. 9.34, purport)
Eternally liberated living entities never come into contact with material nature . . . they are counted among the associates of Krsna. (Teachings of Lord Caitanya, p. 108)
. . .the nitya-siddhas are eternally Krsna conscious without any forgetfulness . . . you should not consider that My associates are ever separated from Me . . . they are almost as powerful as I am . . . they are very, very dear to Me, as I am very, very dear to them. (Nectar of Devotion, p. 205)
First opportunity to associate with Krsna:
The mature devotees, who have completely executed Krsna consciousness, are immediately transferred to the universe where Krsna is appearing. In that universe the devotees get their first opportunity to associate with Krsna personally and directly. (Krsna Book, Ch. 28, 6th paragraph)
There are two kinds of souls: conditioned and liberated, nitya-baddha, nitya-mukta. Just like we are, similarly, there are living entities in the spiritual sky also, but they are liberated. They never become conditioned. We are conditioned. We do not know from when, but we are conditioned. So jiva yara vasi. In this material world, we conditioned, we are residents. But in the spiritual world the residents are all liberated souls. Jagal-laksmi rakhi' rahe yahan maya dasi. (670105CC.NY)
They live in the spiritual world, Vaikuntha planets. Nitya-mukta. Nitya-mukta means eternally liberated. They never come down in this material world.(Bhag. Lecture, June 20, 1973, Mayapura)
The following quotes clearly distinguish that the nitya-baddhas can be liberated and that the nitya-siddhas are never enslaved in the material world even when they come here.
The nitya-muktas are in Vaikuntha jagat, the spiritual world and they never fall into the material world. Those in the material world are conditioned souls, nitya-baddha. The nitya-baddhas can become liberated by controlling the mind because the cause of conditioned life is the mind. (Bhag. 5.11.12, purp.)
Srila Visvanatha Cakravarti Thakura has given a great amount of evidence from the Vedic literatures proving that the humanlike form of the Personality of Godhead and His holy name, abode, paraphernalia and associates are all eternal, spiritual manifestations without any tinge of material contamination. (Bhag. 11.30.5, purport by disciples of A. C. Bhaktivedanta Prabhupada)
There are two kinds of living entities. Nitya-baddha means ever-conditioned. Ever-conditioned means those who are in this material world; they do not know when they came in touch with this material world. Neither do they know when they will be liberated. They are called nitya-baddha, ever-conditioned. And similarly, there are nitya-siddhas. Nitya-siddhas means they never come in contact with this material world, and even if they come here for some business, they do not forget their position. That is nitya-siddha. Try to understand. There are two kinds of living entities: nitya-siddha, nitya-baddha. Nitya-baddhas are within this material world. Beginning from Brahma down to a small ant, insignificant ant, they are all nitya-baddhas.
Anyone who is in this material world, nitya-baddha. And nitya-siddhas, they never come in contact with this material world, and even they come for some business under the order of the Supreme Lord, they do not touch these material qualities. They remain always transcendental. As Krsna remains always transcendental, even though He is in this material world, similarly, Krsna's nitya-siddha associates, they are also transcendental. They never touch this material world. (Bg. Lecture, July 14, 1973, London)
Those who are in the spiritual world, they are nitya-siddha. Nitya-mukta. Nitya-mukta means they never come in this material world. Just like Krsna is nitya-muktya suddha. Similarly the associates of Krsna who come with Him . . . Just like the gopis or the cowherd boys . . . they are all nitya-siddha, nitya-muktya . . . They are in the spiritual form, ananda-cinmaya-rasa, enjoying always spiritual bliss in the association of Krsna. (Bhag. June 19, 1972, Los Angeles)
. . . you should know that the great liberated souls and incarnations who appear from time to time in this material world are not actually coming back, because they are never subject to material contamination or the laws of material nature. (Ltr Srila Prabhupada~Vrndavanesvari, 6 June 1969)
We also mention here that, in regards to the theory that the nitya-muktas fall from the spiritual world and the baddha-mukta (bound who become liberated) do not fall, there is no evidence in sastra supporting or even mentioning this theory, nor do sanskrit terms exist for the mukta-baddha (liberated who become bound). Absolutely no distinction is made in the writings of our acaryas or in sastra between different classes of living entities in the spiritual world in reference to being eligible to fall or not; indeed no direct sastric or acarya reference states that any of them fall down. Neither is there any explicit mention in scripture of fallen nitya-muktas. The theory that the associates of the Lord in the spiritual world fall down implies that nitya-muktas (eternally liberated residents of Vaikuntha) are inferior to baddha-muktas (those bound in the material world who become liberated). This theory insinuates that nitya-muktas must come to the material world to become really fall-proof--to get a better education--i.e., one cannot be a gentleman unless he first visits a brothel. It also implies that bhaya-bhakti, devotion produced by fear or suffering, is superior to prema-bhakti, for only bhaya-bhakti gives complete protection to a devotee, that he will never fall down.