This is a pic of my typical rig at the church I played at for the last decade or so (just left and looking for a new church):
The guitars change weekly at my whim and caprice as I have a passel of them and like to rotate them. Since I play guitar on some songs and bass on others, instead of using a guitar or bass head, I used the little PA head pictured, something the church had lying around unused. That way I could leave the bass plugged into one channel and the guitar plugged into a separate one, so I didn't have to be unplugging and re-plugging in, every time I switched instruments.
The cab is an old Laney 4x12 guitar cab of mine. Normally not a good thing to play bass through a guitar cab, but at the low volume we played at it wasn't a prob. I left the cab at the church 24/7 so I only had to bring in my guitars and effects rather than set up from scratch every week.
I never bothered mic'ing or going direct to the house PA. I figured that way the people who like guitar can sit on my side of the church and those that don't can sit over on the far side and hear less of me.
It's not a big sanctuary so the rig itself was enough.