The reason for God is a work of Christian apologetics, remarkable for the fact that Keller manages to include in it most of the arguments for Christianity that are current among reasonably educated Christians today, and in Part 2 to add some trenchant and convincing theology that is less familiar (to me, at any rate).
Its capacious nature makes it hard to take in at one read, and I wrote a synopsis as a guide for myself. I give it here in case it is useful to someone else. But it is inevitably a personal summary, and no substitute at all for reading the book. In places what follows is rather disjointed, reflecting Keller’s facility in moving rapidly from one idea to the next. I emphasise that this is a synopsis, not a review. The original version included notes reflecting my own responses, some of them disagreeing with Keller, some of them asking questions. But I have removed them, to avoid confusing what I think with what Keller writes.