Well, you've probably already read it, but the I think the ultimate Scifi/Theology book is Frank Herbert's
Dune.
Actually the first four, up to
God-Emporer of Dune, are quite good although I didn't enjoy books two and three (
Dune Messiah, Children of Dune) until I was older.
If you like Stephen King/Clive Barker fantasy-horror, especially if you liked
It, I think Peter Straub's
Shadowland and
Ghost Story are definitely worth a look. Straub's
Hellfire Club is a real page turner once it gets going (slow but enjoyable build up to about page 90 then BAM! Off and running).
For straight science-heavy sci-fi you might give Kim Stanley Robinson's
Mars trilogy a try (Red Mars, Green Mars, Blue Mars). It's got its flaws, but the scientific process of terraforming mars and the political genesis of a new world is interesting.
Lastly,
The Mote in God's Eye by Larry Niven & Jerry Pournelle was another great sci-fi first contact book.
This message has been edited by custard, 02-24-2005 17:35 AM