That pretty much describes religious leaders in general. You hand them money in return for nothing, and the reverends/priests/preachers/whatever spend much of it on themselves and on bigger, shiner churches/temples.
Religion is a scam; that’s part of the point he’s making. People give them money in return for empty promises about an imaginary afterlife. He’s just claiming that black ministers are worse than average. However, whether they are or not, them being a type of priest automatically makes them scam artists; although unlike most scams, in religion sometimes the scam artist actually believes it himself.