"Regarding your first question, a pure devotee is never under the modes of nature. In other words, no material laws apply on a devotee because he is fully under the direction of Krsna. So a devotee can continue his present occupation or he may change it if he likes. Krsna does not force a devotee because the devotee acts spontaneously according to the desire of the Lord; in this kind of loving service there is no question of force. Force is applied only when there is denial of Krsna. Just as the citizens of a state have freedom to follow the laws of the state, that is subordinate freedom, and the freedom of the living entities is also subordinate to Krsna. The clue is given there in the Bhagavad-gita that the living entities are fragmental parts and parcels of the Supreme Lord, this means that all the qualities of Krsna are therefore present in minute quantity in each of His parts and parcels. That is simultaneously one and different philosophy—the living entities thus have free will because they are parts of Krsna and Krsna has free will, but the free will of Krsna is Supreme while the freedom of the parts and parcels is minute. So if the living entity out of love subordinates his free will to Krsna that is his liberation. He is no longer forced to act helplessly, but he acts freely rendering loving devotional service to Krsna in every way. Then we have the practical conclusion from Krsna confirmed by Him in Bhagavad-gita (18:66), 'Just surrender unto Me; and in return I shall protect you from all sinful reactions. Therefore you have nothing to fear.' In this way astral influences are also material and therefore they do not affect the devotee who has taken protection of Krsna's internal energy, by surrendering his life and soul in the service of the Lord.
Your second question about spacemen from other planets; it is stated in the Vedic literature that there are many planets where the inhabitants are more advanced than the inhabitants of this earth planet. So it is not unlikely that such people may have developed space travelling methods. They occupy higher posts in the creation of the Lord and so they may be considered as demigods in the same way as the president is specially empowered by the nation, but this does not mean that such spacemen are necessarily carrying the messages of the Lord, just as the business of the state employee is not to act as the state representative but he acts in his particular job.
Because Krsna know everyone's future does not remove our free will. Someone may commit a theft, and if I know that then I know that he will be captured and punished. That is knowing his future, but know that future does not mean that he had no choice not to commit the criminal act. There are two destinies for every one. One destiny is in Krsna Consciousness and the other destiny is in material consciousness, so if someone is in Krsna Consciousness then Krsna knows his future and if he is in material consciousness and acting in that way then Krsna also knows his future. In this way the free will is not affected by knowing the future of the living being, that is an erroneous conclusion.
In regard to praying to Lord Nityananda Prabhu I have written to you in my last letter that such prayer is quite appropriate. Our only prayer should be in the matter of desiring further development of devotional service and such sincere prayer should be submitted not directly to the lord but through the via-media of His bona fide servitor or representative."
(Srila Prabhupada Letter, February 14, 1970)
"Regarding your first question to explain the statement of Sri Isopanisad that 'even though so many complete units emanate from Him, He remains the complete balance.' In material things there is exhaustion and in spiritual things there is no exhaustion; that is the difference between matter and spirit. From one Krsna there were 16,100 Krsnas in Dvaraka, and each Krsna is as good as the original Krsna. Just like there may be 1000 candles, and all of them light up from one original candle, but still they are of the same candle power as the original candle. Similarly, there may be hundreds and thousands of emanations from Krsna the Supreme, but that does not mean that the Supreme One has diminished in potency, although all other emanations are equally potential.
Regarding your second question, what I said at the airport was that everything is not your's. Everything is Krsna's; you are Krsna's. I hope this will clear the misunderstanding.
If you simply chant your rounds daily as prescribed and stick strictly to the rules and regulations, all these questions will automatically be answered by Krsna as Supersoul. You may refer in this connection to Bhagavad gita, (10:10), 'To those who are constantly devoted and worship Me with love, I give the understanding by which they can come to Me.' and (10:11), 'Out of compassion for them, I, dwelling in their hearts, destroy with the shining lamp of knowledge the darkness born of ignorance.' This process of understanding by devotional service is essential for developing Krsna Consciousness and you all must follow this program assiduously."
(Srila Prabhupada Letter, February 14, 1970)
"Regarding your questions about the difference between the picture of Krsna and the Deity, Krsna is equally there in both these forms. Krsna is so kind that he agrees to appear, for the benefit of the conditioned soul, in eight different kinds of forms. Such form is called archa or the form of the Lord manifested through material agency as metal, earth, wood, painting, stone, jewel, drawing, and mind. The arca is accepted as incarnation of God, and is worshiped by regulations. Generally the installed Deities are so worshiped and the regulative principles should be strictly followed in regard to Them.
I am very happy to learn that you are finding the Detroit atmosphere so blissful, and actually the more you engage yourself in the sincere service of Krsna, the more you will find yourself always blissful.
So far your dreams are concerned, it is very nice that you are thinking about Krsna Consciousness even while sleeping. Krsna is so nice that we want to remember Him even more than twenty-four hours daily. Regarding instructions from the Spiritual Master, there is no need of taking instructions spoken in dream while the Spiritual Master is still present. Lord Jagannath is very kind, and He can also appear in mind in His own form, so why not in your dream."
(Srila Prabhupada Letter, February 19, 1970)
"Regarding what to do with the eyes while on Sankirtan, your suggestion to look into the faces of people and try to convince them of the sincerity of our movement is best. There is no need of artificial things like seeing the spirit soul. We talk, and we talk on Krsna topics—that is all. When we chant, we must concentrate our mind on the sound vibration and in that way everything will be revealed one after another; the form, qualities, pastimes, etc. of the Lord. And this is the way of cultivating spiritual realization.
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. But his relationship with Krsna is never lost, simply it is forgotten by the influence of Maya, so it may be 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 or 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."
(Srila Prabhupada Letter, February 27, 1970)