Work with what you have.
It is very easy to compare church actors to what you see on TV or the silver screen, but unless your church or community playhouse is in NYC or Hollywood, your number of good actors will be fairly shallow.
Don’t expect too much from the auditions. The greatest attribute that I look for is a teachable spirit. I would rather work with a mediocre actor who is willing to learn (and capable) than a decent actor who can’t or refuses to take direction. Sometimes a decent actor is stuck on a plateau and will never change.
Mediocre actors can sometimes suprise you with how much they are willing to risk on stage. They can grow right past where that decent actor was in audition.
Practically, this involves asking an actor to play a scene with a different tone or motivation in audition. If you don’t see or hear any difference, then you most likely will be seeing the same thing in two months during performance.