While the movie diverts at certain key points from the book, it still features great chemistry and lets viewers see how talented Chloe Grace Moretz has become. This movie allows for Moretz to show how diverse her acting can be and at all times keeps in touch with the character of Cameron, a witty, most times quiet teenager who is having a hard time discovering herself while trying to not lose the family that she has left. I would've liked for the movie to touch topics like Cam's parents and the relationship with her grandmother but all in all, if you watch the movie without having read the book, it still is a good movie that touches tough topics like religion and conversion camps. Plus points for the chemistry with Quinn Shepard's character, it's always nice to see actors who can convey actual feelings into the screen.
I feel like this is somehow similar to Boy Erased too.