No priest, rabbi, accredited Christian Science practitioner, or a clergyman or ordained minister of an established church shall be competent to testify in any action, suit or proceeding concerning any information which was communicated to him and entrusted to him in his professional capacity, and necessary to enable him to discharge the functions of his office according to the usual course of his practice or discipline, wherein such person so communicating such information about himself or another is seeking spiritual counsel and advice relative to and growing out of the information so imparted, provided, however, that this section shall not apply where communicant in open court waives the privilege conferred. (1959, c. 646; 1963, c. 200; 1967, c. 794.)