I am not sure as to whether his resignation is a good or a bad thing.
Obviously, the church has embarrassed him repeatedly, but there is the question as to whether he is acquiescing to the Republican bitch slap theory of politics, where they launch an attack not to tell the truth, but to make the Democrat back down, which makes the voters wonder whether he will stand up for them.
I’m inclined to think that it is a losing proposition, because he was 20 years. The Republicans will both claim that it’s the “real Barack Obama”, and that he lacks the guts to stick with the church where he was married and his daughters baptized.