In May 1963--six months before he died--C. S. Lewis was interviewed in his office at Cambridge. It's a fascinating 7-page interchange.
At one point he was asked about his account in Surprised by Joy of his conversion, kicking and screaming, the most reluctant convert in all of England. The interviewer asked whether Lewis felt that he had made a real decision that day. Lewis responded--
I would not put it that way. What I wrote in Surprised by Joy was that 'before God closed in on me, I was in fact offered what now appears a moment of wholly free choice.' But I feel my decision was not so important. I was the object rather than the subject in this affair.I was decided upon. I was glad afterwards at the way it came out, but at the moment what I heard was God saying, 'Put down your gun and we'll talk.'
Interviewer: That sounds to me as if you came to a very definite point of decision.
Lewis: Well, I would say that the most deeply compelled action is also the freest action. . . . I chose, yet it really did not seem possible to do the opposite.
--'Cross-Examination,' in God in the Dock, 261