Hannity speaks about his Roman Catholic beliefs quite often. I've noticed that Rush has interjected an occasioanal pro-life thought into his show, which he didn't do before as I recall. My recollection from his show is he seemed to avoid that topic, now I hear it every now and then.
I can remember one time where Rush made an over top insulting comment about Hillary that had sexual overtones laced in it. A couple of women called in, who said they were Christians, took him to task for his comments as not being of a Christian nature, etc. Rush got angry with both callers and essentially told them off. I've never heard Rush discuss what church, if any, he attends. Religion is a topic he usually avoids.
As numerous polls have shown, a majority of conservative Republicans call themselves Christians (usually from the more conservative denominations of Christianity), so if a station doesn't have the first tier of talkers available to their station then maybe that is a doable option of throwing in a couple of conservative Christian talkers like Janet Parshall, etc. She does do political talk as well as religious talk and has an interesting show, the few times I listened. I might not agree with everything she said, but it was still an interesting show, better than some of the secular third tier talkers I've heard. That might pull in better ratings than a second/third tier conservative only talker who's presentation, etc, is as dry as caulk dust. Of course, if might scare away those conservatives who do not consider themselves to be Christian and are uncomfortable having the Bible and religious thought being mixed with political topics. So it can cut both ways.