The church I attend is a dayschool during the week. And while that may be a concern for an after-the-fact questioning by authorities, it's not much a a concern for me while I'm attending services. If after-the-fact should ever arise, I expect the fact that I was able to save some lives by banging out a few at the bad guy may trump the techincal illegality.
Depending on the weather, I wear a concealment vest with my Glock 27 nestled therein. Warmer weather? I wear the Glock in my right front pocket, safely enshrouded in an Uncle Mike pocket holster. Sometimes, I wear my .357 mag Rossi snubbi tucked into a pancake holster, but I usually have a jacket or sweater over.
If you don't advertise the fact that you are carrying, no one should know enough to be especially aware of whether or not you may be printing.
Just another point here... I asked the president of my local bank how he felt about my carrying in his place of business (technically, it's illegal). His response was to the effect of, if you stop a robbery, you'll likely get a reward. If no robbery is happening, don't show anybody what you're carrying. It could get you in trouble.