In reply to Mary.

This film does tread on sensitive ground. The other aforementioned "God" movies - "Oh God," "Bruce Almighty" and "Evan Almighty" - were more generic in their depictions of the Deity. The Shack presents a clear alternative understanding of the Trinity, and it is this alternative understanding that is a major issue for those who criticize the film.
While you might not notice the differences, neither might an untaught person, whether new to the Faith or still dealing with the call of God through the Gospel. If this opens the door to heretical expressions of the Fatih, we should be aware of that fact, both in order to expose the error and to provide the proper corrective.