Nemesis- In God We Trust
Immolation- lots, but Fall from a High Place is probably best, but pretty much anything else is really good too.
Black Sabbath- After Forever
Neal Morse makes a lot of good Christian rock, Prince of the Power of the Air is one of my favorites. Most of his Transatlantic work is semi-religious too, but probably would all be too long to put on a CD.
Deicide- Once Upon the Cross, even if it is kind of a joke, the intro is too cool to miss.
But the all time best song about religion is clearly Graveland- Blood of Christians on my Sword