Please accept my blessings. I beg to acknowledge your letter of December 3, 1971, and I have noted the contents carefully. I am very pleased that you are making nice progress in Krishna Consciousness. Because we are now getting little respect around the world, therefore we must always be strong in Krishna Consciousness so that our standard will not deteriorate. If we keep our pure standard and maintain our routine regulative work very sincerely, then we shall have certain victory all over the world, know it for certain. Therefore I am urging all my disciples like your good self to go on improving your lives in Krishna's service, and always remain to the high standard of regulative devotional principles, then everything will be successful, and you will be really happy in this life and you are sure to reach the Supreme destination.

Regarding your question, Lord Caitanya is simply making a comparison between the moon and Lord Krishna's Sankirtana movement, because both are radiating benediction on all the living entities. Krishna says in Bhagavad-gita: "I become the moon, and thereby supply the juice of life to all vegetables,'' and in another place "among the stars I am the moon.'' So, directly or indirectly, Krishna is supplying all benediction to everything and everyone, just like the moon gives life to vegetables, without which nothing can exist, and also that moon keeps the great oceans from overcoming the land and destroying everything. Similarly, Lord Caitanya's Sankirtana movement gives spiritual life to all living entities by dint of its transcendental radiation, and also it prevents the demonic class of men from overwhelming the pious class of men, and thus in every way it bestows all benediction, just like at night the moon illuminates everything.

I hope this will meet you in good health and cheerful mood,