"Christianity Today asked more than 100 of its contributors and church leaders to nominate the ten best religious books of the twentieth century. By best books, we meant those that not only were important when first published, but also have enduring significance for the Christian faith and church. We have included books which do not always prompt agreement, but which are important for evangelical Christians to read and contend with. A few "period" pieces also made the list of 90.
"By far, C. S. Lewis was the most popular author and Mere Christianity the book nominated most often. Indeed, we could have included even more Lewis works, but finally we had to say: "Enough is enough; give some other authors a chance.""