Politically, it's definitely controversial. That's perhaps the film's strongest point: that it'll get you thinking and talking about some important issues. It's not a bad little film at all.
It is a "little" film. It has some of the same themes as a true classic like American Beauty. It's no classic, though. On the other hand, it's not easily forgettable, like most little films are.
To avoid spoiling the movie, I'll try to create a good analogy. Imagine a father who gets "raped" in divorce court, losing custody of his children, even though he's a much better parent than his ex is. What if this father then kidnaps his kids, spirits them away to another state, and his kids get their pictures on "have you seen me?" milk cartons.
Then imagine that the father gets arrested and charged with kidnapping. Yet the movie goes out of its way to paint him as the good guy, the innocent victim. That kind of movie would certainly anger a lot of people, wouldn't it? Hillary supporters would sure hate it.
This movie isn't about divorce and custody rights. Instead, it's about an even more controversial theme, to the point where it's likely to anger Trump supporters as well. (The movie doesn't make conservative Christians look good at all.)
So consider yourself warned. I like controversial movies like this, especially those which are a little ahead of their time.