Unto faith the things that are faith's

Hello,

Could anyone paraphrase the words in blue?

Here's my try:

If you call the method is therapy, then it is therapy; if you call the method is a faith, then it is a faith. In other words, a therapy is a faith, vice versus.

Many thanks!

(from Conditioned Reflex Therapy)

I once treated a psychopathic alcoholic with the understanding that it was an experiment and that I promised nothing. He had tried suicide twice before, and had been institutionalized repeatedly. He was mother-bound, and had guilt feelings at being a non-practicing Catholic. His wife felt I had made important progress, but that I was "doing the wrong thing in getting him to loosen up." He agreed. "I know we've gone a long way, but after all, your approach has been scientific. I don't think you pay enough attention to the soul. I have heard a great deal about Alcoholics Anonymous, and if they help me to get more faith in God, I know my troubles will be over." I had planned to get him back to the Church after a half-dozen more sessions, and I tried to persuade him to continue, but to no avail. I asked his wife to remain in touch with me. Her husband kept himself busy with five inspirational meetings a week, and tried to get more faith. A year later he committed suicide. Let us render unto psychotherapy the things which are psychotherapy's; and unto faith the things that are faith's.