My James Blish Appreciation site includes an article comparing the Christian CS Lewis with the agnostic James Blish. Each wrote a theological trilogy and the latter’s refers to the former’s. Also, Blish was a future historian and Lewis’ theological trilogy had replied to earlier secularist future histories by Wells and Stapledon.
Secularist future historians show mankind making its own future without divine help. They also often show religion surviving as an irrational social force, either opposing science or cynically manipulated as a means to social control. Lewis disagreed. In order to address this full sequence of ideas, my article, “CS Lewis and James Blish,” summarises religious and anthropocentric themes in British future histories by Wells, Stapledon and others before considering Lewis, then summarises similar themes in American future histories by Blish and others before considering Blish in relation to Lewis.
The section on American future histories grew as it was written and maybe should have become a separate article that would have been called “Religion in Future Histories.” Heinlein, Asimov, Blish, Anderson, Niven, Pournelle, Burroughs, Simak, Bradbury, Vonnegut, Herbert, Cordwainer Smith and no doubt others all present futures for religion. For a summary and some comments, please see “CS Lewis and James Blish.”
One further comment here: there are different kinds of Christians. Lewis did not believe that only he and his co-religionists were saved or that everyone else was damned. He was a Professor of English Literature whose own fiction incorporated Greek mythology. His theological trilogy presents an Armageddon that is millennia hence and that is clearly mythological in content. Thus, he was not the same kind of Christian as the authors of the recent Left Behind series.