Prabhupada -a sakti avesa avatar

 While the religious systems based upon the teachings of these personalities no longer follow the original teachings of their masters, we, the people of this age have been given yet another great opportunity to directly associate with the pure representative of the Supreme Personality of Godhead coming from the spiritual world. This time, he has spred the science of love of God all around the world and represents the top most pinnacle of all sainly teachers. It is His Divine Grace A.C.Bhaktivedanta Swami Prabhupada

Let's look at some of the definitions of a nitya-siddha(eternally liberated) devotees in the following quotes:

TRANSLATION

O my worshipable Lord, because the seed of lusty desires, which is the root cause of material existence, is within the core of everyone's heart, You have sent me to this material world to exhibit the symptoms of a pure devotee.

PURPORT

Bhakti-rasāmṛta-sindhu has given considerable discussion about nitya-siddha and sādhana-siddha devotees. Nitya-siddha devotees come from Vaikuṇṭha to this material world to teach, by their personal example, how to become a devotee. The living entities in this material world can take lessons from such nitya-siddha devotees and thus become inclined to return home, back to Godhead. A nitya-siddha devotee comes from Vaikuṇṭha upon the order of the Supreme Personality of Godhead and shows by his example how to become a pure devotee (anyābhilāṣitā-śūnyam [Bhakti-rasāmṛta-sindhu 1.1.11]). In spite of coming to this material world, the nitya-siddha devotee is never attracted by the allurements of material enjoyment. A perfect example is Prahlāda Mahārāja, who was a nitya-siddha, a mahā-bhāgavata devotee. Although Prahlāda was born in the family of Hiraṇyakaśipu, an atheist, he was never attached to any kind of materialistic enjoyment. Desiring to exhibit the symptoms of a pure devotee, the Lord tried to induce Prahlāda Mahārāja to take material benedictions, but Prahlāda Mahārāja did not accept them. On the contrary, by his personal example he showed the symptoms of a pure devotee. In other words, the Lord Himself has no desire to send His pure devotee to this material world, nor does a devotee have any material purpose in coming. When the Lord Himself appears as an incarnation within this material world, He is not allured by the material atmosphere, and He has nothing to do with material activity, yet by His example He teaches the common man how to become a devotee. Similarly, a devotee who comes here in accordance with the order of the Supreme Lord shows by his personal behavior how to become a pure devotee. A pure devotee, therefore, is a practical example for all living entities, including Lord Brahmā.

SB 7.10.3

Like these two brahmanas of Vidyanagara, there are many devotees who are eternal servants of the Lord. They are specifically known as nitya-siddha, eternally perfect. Although the nitya-siddhas appear in the material world and seem to be common members of the world, they never forget the Supreme Personality of Godhead in any condition. This is the symptom of a nitya-siddha.

There are two kinds of living entities--nitya-siddha and nitya-baddha. The nitya-siddha never forgets his relationship with the Supreme Personality, whereas the nitya-baddha is always conditioned, even before the creation. He always forgets his relationship with the Supreme Personality of Godhead. Here the Lord informs the two brahmanas that they are His servants birth after birth. The phrase birth after birth refers to the material world because in the spiritual world there is no birth, death, old age or disease. By the order of the Supreme Personality of Godhead, the nitya-siddha remains within this material world like an ordinary man, but the only business of the nitya-siddha is to broadcast the glories of the Lord. This incident appears to be an ordinary story about a marriage transaction involving two ordinary people. However, Krsna accepted the two brahmanas as His eternal servants. Both brahmanas took much trouble in these negotiations, just like mundane people, yet they were acting as eternal servants of the Lord. All nitya-siddhas within this material world may appear to toil like ordinary men, but they never forget their position as servants of the Lord.

C.C. Madhya lila 5.113

Unless Sri Krsna Caitanya Mahaprabhu discloses the fact, no one can understand who is actually a great devotee of the Lord engaged in His service. It is therefore said in Caitanya-caritamrta (Madhya 23.39), tanra vakya, kriya, mudra vijneha na bujhaya: even the most perfect and learned scholar cannot understand a Vaisnava's activities. A Vaisnava may be engaged in governmental service or in a professional business so that externally one cannot understand his position. Internally, however, he may be a nitya-siddha Vaisnava-that is, an eternally liberated Vaisnava. Externally Mukunda dasa was a royal physician, but internally he was the most liberated paramahamsa devotee. Sri Caitanya Mahaprabhu knew this very well, but ordinary men could not understand it, for the activities and plans of a Vaisnava cannot be understood by ordinary men. However, Sri Caitanya Mahaprabhu and His representative understand everything about a devotee, even though the devotee may externally pretend to be an ordinary householder and professional businessman.

C.C. Madhya Lila 15.121

A nitya-siddha pure devotee in other words comes from the spiritual world and although he might appear to be just like a common man, he's never contaminated by the material nature. Srila Prabhupada is such a nitya siddha. Although appearing as an ordinary man from Calcutta, he's never forgetful of his relationship with Krsna and his only buisness is to broadcast the glories of the Lord. Now, let us examine the nature of an avatar.

"Without being empowered by the direct potency of Lord Krishna to fulfill His desire and without being specifically favored by the Lord, no human being can become the spiritual master of the whole world... Only an empowered personality can distribute the holy name of the Lord and enjoin all fallen souls to worship Krishna.

By distributing the holy name of the Lord, he cleanses the hearts of the most fallen people; therefore he extinguishes the blazing fire of the material world. Not only that, he broadcasts the shining brightness of Krishna's effulgence throughout the world. Such an acarya or spiritual master should be considered non-different from Krishna--that is, he should be considered the incarnation of Lord Krishna's potency. Such a personality is krsna-lingita-vigraha--that is, he is always embraced by the Supreme Personality of Godhead, Krishna. Such a person is... the guru or spiritual master for the entire world, a devotee on the topmost platform, the maha-bhagavata stage."

(Srila Bhaktisiddhanta Sarasvati Thakura, Anubhasya, cited in Sri Caitanya-caritamrta, Madhya-lila 25.9, Purport)

No one ever before had done what Srila Prabhupada has done. He has introduced the yuga-dharma Hare Krsna chanting in the whole world. He has established 108 bona fide Krsna conscious temples in all the major cities in the world and made people of all races, ages, genders and occupations to follow the regulative principles of the Krsna devotee lifestyle. It is only thanks to Srila Prabhupada that the Hare Krsna mahamantra became a household word. Hardly anyone would be able to deny that Srila Prabhupada is that empowered personality. Srila Prabhupada further confirms such a conclusion in his Nectar of Instruction where he indirectly reveals that he really is an empowered mahabhagavat(the first class pure devotee), engaged in the confidential service of the Lord. Srila Prabhupada also warns that treating a devotee on such a platform as an ordinary man means a destruction on the spiritual path.

Those who think that Kṛṣṇa consciousness is limited to a certain section of people, a certain section of devotees or a certain tract of land are generally prone to see the external features of the devotee. Such neophytes, unable to appreciate the exalted service of the advanced devotee, try to bring the mahā-bhāgavata to their platform. We experience such difficulty in propagating this Kṛṣṇa consciousness all over the world. Unfortunately we are surrounded by neophyte Godbrothers who do not appreciate the extraordinary activities of spreading Kṛṣṇa consciousness all over the world. They simply try to bring us to their platform, and they try to criticize us in every respect. We very much regret their naive activities and poor fund of knowledge. An empowered person who is actually engaged in the confidential service of the Lord should not be treated as an ordinary human being, for it is stated that unless one is empowered by Kṛṣṇa, one cannot spread the Kṛṣṇa consciousness movement all over the world.

When one thus criticizes a pure devotee, he commits an offense (vaisnava-apardha) that is very obstructive and dangerous for those who desire to advance in Krsna consciousness. A person cannot derive any spiritual benefit when he offends the lotus feet of a Vaiṣṇava. Everyone should therefore be very careful not to be jealous of an empowered Vaiṣṇava, or a śuddha-vaiṣṇava. It is also an offense to consider an empowered Vaisnava an object of disciplinary action. It is offensive to try to give him advice or to correct him. One can distinguish between a neophyte Vaiṣṇava and an advanced Vaiṣṇava by their activities. The advanced Vaiṣṇava is always situated as the spiritual master, and the neophyte is always considered his disciple. The spiritual master must not be subjected to the advice of a disciple, nor should a spiritual master be obliged to take instructions from those who are not his disciples.

NOI ch.6