It's very different than Part One, which was pretty much all esoteric world building. Part Two is much more streamlined and accessible, which is important because shits about to get real weird, real fast in Messiah
I actually felt Part 1 was more accessible than Part 2. I feel like Part 1 built slowly and Part 2 crammed a lot of story in which is why I didn't really know what to think after my theater viewing. Now I actually feel like I like Part 2 better. That cinematography and that score!
I actually never read Messiah so I need to get ok that. If I remember correctly the start of a war isn't even in the first book.