It's probably worth noting that HuffPo leaves out the immediatly prior comments as well as the full context, even though it cites as source an article that didn't. He started with:

"You all have to forgive me, but this feels like a pulpit and I am a preacher," he says during the talk. "It's just a natural thing when I get into this setting, ya know?"

So he's saying to his 100% Christian audience that he's going to deliver a sermon, keep that in mind.

Cain speaks for nearly a half an hour and despite a couple fleeting "999" mentions, keeps his speech to topics of faith and his recent battle with cancer. He begins with a story about how he knew he would survive when he discovered that his physician was named "Dr. Lord," that the hospital attendant's name was "Grace" and that the incision made on his chest during the surgery would be in the shape of a "J."

"Come on, y'all. As in J-E-S-U-S! Yes! A doctor named Lord! A lady named Grace! And a J-cut for Jesus Almighty," Cain boomed.

So the man is preaching, literally, to an audience, and making personal reference to his grave illness which he believes he survived by the Grace of God, of what he views (perhaps seriously, perhaps jokingly, probably both) to have been signs he was in God's hands. I'm Christian, and I wouldn't think twice about my doc's religion, but I admit if I were going in for treatment for something really bad and had been spending a lot of time praying for it, I would probably feel a certain elation if say, every name tag of medical personnel treating me had stuff like "Lord" or "Angel" on it, or even something absent obvious religious connotation like "Dr. Asklepios" or "Dr. Ace Surecut" and "Nurse Speedy Recovery", and it might supply a little extra confidence which would be spoiled if the rhythm was broken or my surgeon walked in with a name tag that said "Deth" or "Forlorn" or tossed of a pre-anesthesia joke about how he was glad he got called in because it broke up his golf game and he'd had half a dozen mulligans. Logical or not those would understandably make someone a touch nervous. So Cain's basically just acknowledging the guy's name broke his mental crutch about being in God's hands but finding out the guy was Christian made him feel better... if I was thinking and hoping God might be intervening on my behalf, I would too. It wasn't very PC but I don't think in context it's the assault on Islam it's being portrayed to be, and I'd cite that this morning only very openly left wing blogs or journalists are discussing it, besides the initial article... even though his trip and speech were made on Friday.