It is not "preachy" at all. In fact I don't think you could really even tell what religion it really is. This is mostly about how to keep marriage together as in the vows.
If you go to www.fireproofthemovie.com you can get more info , see some behind the scenes, some trailers,still pictures, etc.
It really shows a pretty realistic view of how a marriage could end when the couple is not working together but leading seperate lives and how if it is important enough to you to save your marriage, what hard work it can be to save it.
I know several of the people in and behind the scenes. This movie is truly a community effort and is very professional. There are many opportunities for tears and laughs and it is NOT a film about take my religion or you are nothing.