Creativity vs. Entertainment

For the past several months I’ve been working on a story that I’d like to make into a film.  But, as a Christian, am I “wasting my life” by spending time, money and effort on a project that’s not inherently “Christian” or directly glorifying to God?  Some folks would say yes.  Some would not.

Was C.S. Lewis “wasting his life” when he wrote The Chronicles of Narnia?

I guess I’m looking for a healthy balance between creativity and entertainment.