Every so often before church he asks if he can preach. Especially if I mention that there is a special speaker or visiting evangelist. I guess in support of Isaiah's aspirations, the kids have taken to playing church occasionally. Isaiah can be a little loud. The congregation tends to shout a lot of "AMEN" and "PREACH IT!" Sometimes the church gets persecuted by a rogue gunman with a Nerf gun who breaks in. Then I hear random shouts of "STOP IT! Don't shoot me I am preaching."
Occasionally there has been a "bad guy" hauled out of the little church and taken to a jail in the back corner. Someone from the little church pays a jail visit and he is often saved and then he attends the church too.
Apparently, Isaiah the preacher really only has one sermon entitled "You Can't Serve Sin." Our family is participating in a church challenge to memorize the chapter of Romans 6. In going over Isaiah's verses with him he had a long pause and said "Wait! this is my favorite part.... 'that henceforth we SHOULD NOT SERVE SIN.'" (Romans 6:6) "Mom, I preach on that one."