What should we do if church treasurer stole $30,000 from the church's accounts?

You are not required to press charges but it would be incredibly dumb not to and I believe you have a moral responsibility to do so. This person needs to be in jail but at the very least, needs to never hold a position of financial trust ever again and a conviction will help insure that never happens. So basically what you are doing with your internal. turn the other cheek, repayment plan is potentially putting other people at risk in the future of having money stolen. Maybe next time it's more than $30,000 and maybe its from someone who can't afford to lose the money - is the church gonna mop up future messes? If you don't press charges, I believe you would have an obligation to mop up future messes.