Joe.
I don't think it's a static problem. As Bob L says, sounds like a reception problem. Make sure (Shure!) the receiver is relatively close to your minister..You might have to hard wire the receiver to the amp/PA whatever, if it's a long way away.
As long as your chappie doesn't tend to go walkabout too much (ie, doing his sermon from the far end of the graveyard!) it should be fine! Also in my experience, the Transmitter eats batteries for breakfast!
I use Radio In-Ear monitoring, and in a 4 hour dance, I always change the batteries half way through. (I have a supply of re-chargeables permanently cooking at the back of the stage!)
So, sounds definitely like a reception/low battery problem.
Good luck!