Tis fully legal, but I'm also in the "I CC in church" camp. I've open carried at a few of our outside events, don't get me wrong, but when I'm in the church building I don't want to be a distraction for any visitors - or even more, something that takes away from their purpose there, which has nothing to do with me.
I happen to know that there are at least 4 other people there also CCing at the same time
Not a church you want to start a fuss at