Personally, I PREFER to go right into the church PA, but lately I've been going just directly into my amp. For some reason, if I go direct into the PA, my bass takes one side of the PA output and leaves only the other side for the vocalists' mics. I'm going to experiment with some different cabling arrangements when we rehearse Saturday, because I prefer the balanced sound of the bass in the mix with all the other inputs, including the electronic drums that are played through the PA. Right now we have keys, drums and voices coming from the speakers in the back of the church and my bass coming from my amp at the front.
By the way, I believe DI is for Direct Input, not Direct Injection. When I do go into the church PA, I use a Sansamp BDDI (Bass Driver Direct Input)

Peace,
James