The great difficulty is to get modern audiences to realize 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 good for society or something of that sort. Now a clearly maintained distinction between what the Faith actually says and what you would like it to have said or what you understand or what you personally find helpful or think probable, forces your audience to realize that you are tied to your data just as the scientist is tied by the results of the experiments; that you are not just saying what you like. This immediately helps them to realize that what is being discussed is a question about objective fact—not gas about ideals and points of view.
C.S. Lewis, God in the Dock; via Michael Horton, Christless Christianity