Check Craigslist ads - sometimes, you can find opportunities there.
Start to network; get to know musicians and chips directors at different churches and tell them what you're looking to do. Depending on the church, this may be a good way to get a foot in the door.
People will say look for God in what you do and play - as a fellow Catholic, I know that ain't happening. Treat this like a job; network a lot in your area.
My experience as a bassist in a gospel church was interesting because I never grew up with their song arrangements. It was also impromptu - the congregation could break into song at any moment. (Black church, nice place.) I couldn't hang not because I wasn't a good musician, but because I didn't know the church, the culture (I'm black, still couldn't hang), and the norms. It's not just hymns - it's the little in-betweens, prayer vamps, following the flow of the congregation and the energy in the room, supporting the minister when the word hits him, etc. For this kind of church the music is the worship - you have to be able to speak through it and it through you, and that is less musicianship and more culture.
To avoid this I'd suggest finding a praise band situation where your set is very structured. You want to know what you will be playing and avoid surprises.
Good luck. If you can find it it'll be fun!