Alot of bands start out as "church related" to get venues originally and mediocre funding/support from the get-go. This doesn't really make them church bands. But I have to concur on the fact that "Christian 'rap'" sucks.
It's a pretty easy crossover. Just change the word "Jesus" to "Baby".
Look up some of the lyrics sometime. They're abstractly related to Christianity.
There are lots of bands like that. Deicide does it, but they kind of approach it from the other side. In terms of bands who talk about it in not such a "fuck God" way, Grave Digger comes to mind. The album "The Last Supper" is almost entirely about Christianity. The songs "The Last Supper" and "Divided Cross" are a couple examples. My favorite one, though, is Crucified. Here are some lyrics from Crucified (which I actually had trouble finding.. the first few sites were missing the first stanza, wtf?):
Through iron bars I see the cross
They built it upon the hill
They're sharpen the nails to pierce my hands
They plait the crown of thorns
Father tell me what went wrong
My whole life my faith was strong
Father tell me why should I die
This screaming mob yells crucify
My curse comes true I have to die
Why I am crucified
The walls around me cold and grey
Cramp my soul, nothing more to say
I gave my life for the human brood
But they've payed me in blood
