The following interview is much more revealing.
I know that it's easy to criticise some things in the movie The Shack. Any portrayal of the eternal relationship we call the Trinity will be problematic (especially when using human actors).
We know that the Father and the Son are always spoken of as male in the Bible. But we also know that God is neither male nor female (see here).
We know that the Father was not crucified. But we also know that the Father suffered just as much as the Son when he was crucified.
I think the film portrays these things very powerfully and for that it is to be commended. I don't agree with everything in the film, but I do encourage people to watch it. I'm sure you'll appreciate God more if you do. (If you think God gives up on some people, or that he is unable to save some people, I strongly recommend you read chapter four of The Inescapable Love of God by Thomas Talbott.)
The thing I like most about the movie is it rightly represents God as being truly worthy of our complete and absolute trust. God only wants one thing from us; he wants us to trust him. (By the way, if you say you trust your doctor you will not only take him at his word, you'll also take the medicine he prescribes. If you refuse to follow his directions, you're lying to yourself; you don't really trust him.)
If you are a Christian, you might appreciate the sermon "The Eloi." It begins with the words:
"My God, my God, why hast thou forsaken me?”
It was written by C.S. Lewis' favourite author.