From the beginning where he believed books should be burned and for a reason, to where books were a beautiful thing. He may have learned a hard way when his house got burned down because the chief found out. And his house is done so he goes to the river by the forest and he runs into people who live there. They apparently tell him that they both remembered one line from The Bible. Montag generously volunteers to say parts of The Bible but his brain was a little foggy to remember because what has all happened.
In the end of the book Montag and the ex-professors are the only ones alive because of a bombing. So the ex-professor's (book people) and Montag decided to rebuild society so people can express themselves. Then Montag remembers a quote from the “Book of Ecclesiastes” that said, “ A time to sew, a time to reap, and the tree of life.” His beliefs at the end of the book changed immensely from the beginning to the end. At the end he did not think anything of them but at the end he enjoyed them and enjoyed the mystery and curiosity of it