All mortals tend to turn into the thing they are pretending to be. This is elementary.
I see few of the old warnings about Worldly Vanities, the Choice of Friends, and the Value of Time. All that, your patient would probably classify as "Puritanism" -- and may I remark in passing that the value we have given to that word is one of the really solid triumphs of the last hundred years? By it we rescue annually thousands of humans from temperance, chastity, and sobriety of life.
He can be made to take a positive pleasure in the perception that the two sides of his life are inconsistent. This is done by exploiting his vanity. He can be taught to enjoy sitting beside the barber on Sunday just because he remembers that the barber could not possibly understand the urbane and mocking world which he inhabited on Saturday evening, and contrariwise, to enjoy the friends all the more because he is aware of a "deeper," "spiritual" world within him which they cannot understand.