I'm actually studying in seminary at the moment, and I've had a couple of games put out there. Eldritch Ass Kicking is my first printed game, distributed by Key20 Publishing (now Key20 Direct). I did work on the recent Noumenon RPG from Abstract Nova. I also have a couple of products on RPGNow - I'm just an indie publisher really, but I'm a Christian... licensed minister at the moment.
There is a lot of rich possibility in using the Bible as a background for RPGs, but I think there are some examples of that out there... like Green Ronin's Testament D20. I think a small press company, Visionary Entertainment, had something out for a while, though I don't know if they are still around. Dragonraid sort of has notoriety, but it does well because it has specific design goals (in a nutshell - get kids to memorize bible verses through a game). Multiverser was written by M.J. Young, a great theologian. There are other ones out there - mostly small press or free (like Claymore and Seth Ben-Ezra's work).
Is there a market for it? Not really. The big Christian publisher of games is Cactus Games, and they do well because, first and foremost, they design rockin' games. They have never done a Christian rpg - collectible card games and board games are their style. (One of their popular ones is Settlers of Canaan, a Christian remake of Settlers of Catan.)
In reality, Christian gamers play the same stuff you play - games where there is good and evil and people have to make tough moral decisions. Really, it's a lot like life perhaps. I like running and designing games that are just simply fun, that make you laugh. I mean, a staple of Jesus' ministry was to get people around a table and eat and talk. (Maybe he was a gamer?) But I'm also interested in bringing in larger themes into my games, some of which parallel biblical themes... like exodus, exile, a prophet to a hard-necked people, compassion to your enemies, strangers in a strange land, being counter-cultural, fighting the man, standing with the poor, loving the unloved... Any of these themes could make an awesome backdrop for a roleplaying game.
So yeah, the bible and Christian spiritual tradition has much that could be used as inspiration or support for a game -- but why does the game have to be... Christian persay?