In the Santa Rasa stage there is a chance of meeting a devotee by the Grace of Lord Krishna, and therefore, generally, the next birth is human being. Unless there is a great fall-down on account of various reasons, any transcendentalist, either personalist or impersonalist, if he makes regular progress in the regulative principles, even though he does not finish, the whole program, is sure to get his next birth in a good family - generally a rich man's or a pure Brahmin's—that is confirmed in the Bhagavad-gita.
Letter to Bhagavan das, 28 January, 1970