Derek Webb was formerly one of the lead members of Caedmons Call. One of my favorite songs of CC is "Somewhere North" from their 40 acres album. Derek did the vocals for that song and I believe he wrote it as well. Caedmons Call as well as Derek Webb are all openly reformed and make it obvious through their songs. Derek attends a Presbyterian church in Tennessee.
I would recommend checking out his new album (it is free! why not?) and then if you like that or his older stuff from his Caedmon´s Call days, then check out his other solo albums especially She Must and Shall Go Free which is his first solo album dedicated Christ's Bride - the Church.