Our town has an annual service for Church unity. I just found out that the next one will be at the Pentecostal church -- my old Pentecostal church. Our choir is also supposed to be singing. I would happily worship with the folks there, for all our disagreements, but this is the church whose pastor, less than six months ago, received a very blunt letter from me detailing his abuse and manipulation. It's not a forgiveness issue; it's just after a letter like that, you can't just turn up at someone's church having not seen them face-to-face in a couple years and sweep history under the carpet.
I think the choir are going to be a tenor down. Sometimes, grace just takes a little longer to work in the real world.