Sixty years ago, London publisher Geoffrey Bles first released a revision of four sets of radio talks by an Oxford literature don. The book was called Mere Christianity, and there was nothing "mere" about it. A somewhat disjointed set of C. S. Lewis's views on a wide range of theological, philosophical, and ethical matters, the book became the most important and effective defense of the Christian faith in its century.
As Mere Christianity (henceforth "MC") goes into its seventh decade of publishing success, rivaled still by no other apologetic, it's worth taking a look at its unlikely success.
Why It Shouldn't Have Worked
The first reason why MC should not have worked is rather basic: It doesn't deliver what its title promises. It does not do even what John Stott's classic Basic Christianity does—namely, outline at least the basics of evangelicalism's understanding of the gospel. Given the title's own promise and Lewis's express intent of offering "mere Christianity," we get something substantially less than that, as I think Puritan pastor Richard Baxter, from whom the phrase comes, would affirm.
Furthermore, MC offers not only less than "MC," but also more: Lewis's own opinions about domestic relationships, marriage, and gender; and his particular take on the vexed question of God and time (which, in my view, has powerfully perpetuated Christian Platonism and its "timeless God" among many people who have never read Plato). The danger here is the danger that resides also in C. I. Scofield's dispensationalist notes to his famous Reference Bible. (I recognize that this is perhaps the first time anyone has claimed that ...1