I didn’t find any of it boring. I found it fascinating. You have to read the book though to understand the final scenes in order to realize it is a film about God. Some people understood it, but many left the theater wondering what happened.
Some people just don’t like movies that want you to think. Momma always said only boring people get bored.
I also read the book. Whatever qualities the film possesses is wasted in lethargic pacing and boring, cold, undeveloped characters.