I love playing in churches.
Obviously, first to be able to worship with my instrument, but for the musical part, it's great to play with different musicians every week, with sometimes great musicians, sometimes not...
And a think it's great school to have a new set list every week with really short time to rehearse which teach to get efficient.
I really enjoy the thing to "own" the place which makes it really easy to have endless jam sessions after service.
But it definitely can be totally different from one church to another.
my church in France : great groovy musicians, at least for the rhythm section. Really serious an efficient way to work. I'm usually playing saturday after-noon for youth group, plus 2 services on sunday and an always automatic jam on sunday nights so plenty of time to play. Only regret, always keep the volume down...(about 250 people)
1 semester in Chile : from far the smallest church I played in, about 40 people on a good sunday and about 10 of those 40 playing ! Completely unorganized way to deal with it. During the 2 hours practice 90% of the time, some members of the worship team weren't practicing (late, eating, discussing, on the phone, leaving earlier...) almost never music sheet, and when no one knew the tune we would listen to it once or twice (never more) on a crapy cd player. A lot of fun
1 semester in Rhode Island in a Baptist Church : That's right, no dancing, but pretty usual pop rock hillsongish stuff with a volume always REALLY low with no amp on stage... completely frustrating for the sound part... but also regular great jam sessions
my current semester in Virginia : really good quality Jesus Culture/Hillsong style, never any technical difficulty for the bass player, but it feel so nice to play full drive, w/out volume limitation, w/out any need of music sheet, just enjoying playing and worshiping. And it worship band rotation so we have 2 practice per service which makes it really comfortable.
wow I wrote a useless novel, my bad.