I like both Lewis and Tolkien, but I do think that the more explicit approach—if not over the top—is more effective in terms of touching people with the gospel. The gospel is sufficiently clear in The Lion, the Witch and the Wardrobe that a person could come to faith in Christ through it, and some have. Coming to Christ through Lord of the Rings would be a stretch. Now, of course, a book can be good without drawing someone to Christ, but I am in favor of very good books that also have some impact on people's spiritual lives and show them their need for the Lord.
Do You Put Your Theology into Your Fiction Novels?
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Randy Alcorn answers the question of how his theology of heaven manifests itself in his fiction novels. This video clip was excerpted from Randy's Eternity 101 DVD class.