The great difficulty is to get modern audiences to realise that you are preaching Christianity solely and simply because you happen to think it true; they always suppose you are preaching it because you like it or think it is good for society or something of that sort.… This immediately helps them to realise that what is being discussed is a question about objective fact—not gas about ideals and points of view.… Do not attempt to water Christianity down. There must be no pretence that you can have it with the supernatural left out. So far as I can see Christianity is precisely the one religion from which the miraculous cannot be separated. You must frankly argue for supernaturalism from the very outset.

C.S. Lewis
‘Christian Apologetics’
God in the Dock