The true power of imagination is it can be used to drive us toward reality and others. Jesus' command about treating others as you would have them treat you is an ethic based on imagination. I have to imagine what it is like for the other in order to act.
Spokane has joined in the billboard wars. As Thomas J. Brown reported a few weeks back on SpokaneFAVS, our city is the latest in which an atheist group has purchased advertising to argue, among other things, that "Truth is real; God is imaginary."
Fantasy also has a tradition within Christian culture. George MacDonald, C.S. Lewis, and J.R.R. Tolkien explore faith themes in their imaginative worlds.