It is not a matter of having priests and nuns on the set, not a matter of explicit reference to Catholic things, but rather the Dantesque vision.

On Being a Catholic Writer

by Ralph McInerny

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You can take a course in watercolors, you can take piccolo lessons, you can take a writing course. The emphasis will be on technique, how to do it. What the course cannot give you is vision or a voice. 
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It is with something more than technique that the question of the Catholic writer arises. Stories are about people doing things, pursuing goals, meeting difficulties, overcoming or being overcome, succeeding or failing. The men and women in stories face problems we all face, and this can interest us in the account of how they fare. Now this is true of commercial short stories as well. 
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When Dante dedicated the Paradiso to Can Grande della Scala, he said that the literal meaning of the Divine Comedy is the way in which human beings by their own free acts earn eternal punishment or reward. That is the vision of human action that makes fiction Catholic. It is not a matter of having priests and nuns on the set, not a matter of explicit reference to Catholic things, but rather the Dantesque vision. 
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