Toward Ecosophy

Ok, I've begun Contra Celsum and the first thing that jumps out and he is that Origen does not deny that there is a secret, esoteric Christian doctrine taught only to initiates; he only claims that that doesn't make it any different from the philosophical schools or the mystery schools. Robert if you happen to see this tonight, I recall that you have several times said that there is evidence of a secret initiatic tradition in Christianity surviving in certain Orthodox monastic traditions, but I can't remember the details. Could you point me to a reference to it?