It doesn't have to be Christian to be faith-based.
By faith I mean you have to believe in free will. It's not like believing in something tangible, like the moon, or cars, "free will" is fleety and difficult to pinpoint.
We tend to see a large selection of options as evidence of free will, yet everyone picks a single option each time they act, that option is normally picked without much consideration, it simply follows your usual pattern, which in turn is a result of a series of interactions with ones environment. As your options decrease, so does the freedom of your will
If I tie someone to a chair, their freedom is limited and their will is powerless. They're gonna have to adjust their will to something they can achieve :]
I'm rambling now, point is, "free will" is like "art" or "meaning of life", it is a philosophical concept