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. . . .
The Christian story is precisely the story of one grand miracle, the Christian assertion being that what is beyond all space and time, what is uncreated, eternal, came into nature, into human nature, descended into His own universe, and rose again, bringing nature up with Him. It is precisely one great miracle. If you take that away there is nothing specifically Christian left.