In any legal or quasi-legal trial, hearing or proceeding before any court, commission or committee no regular or duly ordained minister, priest or rabbi shall be required, in giving testimony, to disclose any confidential communication properly entrusted to him in his professional capacity and necessary and proper to enable him to discharge the functions of his office according to the usual course of practice or discipline of his church or religious body. This prohibition shall not apply to cases where the party in whose favor it is made waives the rights conferred.