WannabeWriter,
I sympathize with your concern. My novel The Coppesmith features a serial killer torturing and murdering evangelical ministers. In one scene, he whips a man to death with a cat-o'-nine-tails. The scene is critical to the story, as how he kills is significant to understanding what he's doing and why.
I plunged in and went for it. I was less concerned with the aftermath, because the victim doesn't survive, but it did effectively portray my killer as a consciousless SOB.
Is it over the top? Probably for CBA or ECBA. But they only represent a fraction of the Christian Market, and new publishers are cropping up willing to push the boundaries of realism. In the regular ABA market, the book is tame, comparatively speaking.
Write it in a way that produces a visceral emotional reaction in you, as opposed to, say, nausea. That's a more honest route, I think.