>>24688903 (OP)
>>24688939
>>24689077
>>24692757
It was all of these reasons. My personal theory is he was beginning to realize the God shaped hole in his life. He was seeing, however dimly, that Jesus Christ is real, and laying down your life for Him is scary. I sincerely hope he found God in his last moments.
You can see threads of this in his work. He talks a lot about worship as an agnostic, he mentions C.S. Lewis in an interview, and the Pale King has a Christian character which is quite profound.