If they must be Christians, let them at least be Christians with a difference. Substitute for the faith itself some Fashion with a Christian colouring. Work on their horror of the Same Old Thing.
The horror of the Same Old Thing is one of the most valuable passions we have produced in the human heart—an endless source of heresies in religion, folly in counsel, infidelity in marriage, and inconstancy in friendship. The humans live in time, and experience reality successively. To experience much of it, therefore, they must experience many different things; in other words, they must experience change. And since they need change, the Enemy (being a hedonist at heart) has made change pleasurable to them, just as He has made eating pleasurable. But since He does not wish them to make change, any more than eating, an end in itself, He has balanced the love of change in them by a love of permanence. He has contrived to gratify both tastes together in the very world He has made, by that union of change and permanence which we call Rhythm. He gives them the seasons, each season different yet every year the same, so that spring is always felt as a novelty yet always as the recurrence of an immemorial theme. He gives them in His Church a spiritual year; they change from a fast to a feast, but it is the same feast as before.
Now just as we pick out and exaggerate the pleasure of eating to produce gluttony, so we pick out this natural pleasantness of change and twist it into a demand for absolute novelty.
—Screwtape, in The Screwtape Letters by C.S. Lewis (in The Complete C.S. Lewis: Signature Classics, p. 257-258).