Using a Compressor and EQ for Church Services

Do you need a compressor on every channel? No.
Excessive compression can:
1. Sound unnatural
2. Increase background noise
3. Move the system closer to feedback
In spite of this, I use compression a lot. If you're only using a few channels at a time, you don't need to do much of anything (our singers are using Shure SM58 microphones, so we have to boost a lot of high frequencies (5k), cut the lows, and cut a tiny bit around 500hz). But in a larger band with many musicians, it's more difficult to get clean sound. I'll briefly discuss compression and EQ for instruments.