1. Acaryas descend out of compassion, to save suffering men

    In that planet of Satyaloka, there is neither bereavement, nor old age nor death. There is no pain of any kind, and therefore there are no anxieties, save that sometimes, due to consciousness, there is a feeling of compassion for those unaware of the process of devotional service, who are subjected to unsurpassable miseries in the material world.

    (SB 2.2.27, text)

    From Srila Prabhupada's purport:

    The Vedic wisdom guides us to understanding our relation with the Supreme Lord Sri Krsna and to acting accordingly in order to achieve the desired result of returning home, back to Godhead. But materialistic men do not understand this. They want to make a plan to become happy in a place where there is no happiness. For false happiness they try to reach other planets, either by Vedic rituals or by spacecraft, but they should know for certain that any amount of materialistic adjustment for becoming happy in a place which is meant for distress cannot benefit the misguided man because, after all, the whole universe with all its paraphernalia will come to an end after a certain period. Then all plans of materialistic happiness will automatically come to an end. The intelligent person therefore makes a plan to return home, back to Godhead. Such an intelligent person surpasses all the pangs of material existence, like birth, death, disease and old age. He is actually happy because he has no anxieties of material existence, but as a compassionate sympathizer he feels unhappiness for the suffering materialistic men, and thus he occasionally comes before the materialistic men to teach them the necessity of going back to Godhead. All the bona fide acaryas preach this truth of returning home, back to Godhead, and warn men not to make a false plan for happiness in a place where happiness is only a myth.