The Archbishop of Caterbury, who sits on Parliament's banking standards commission, said at a Bible Society-organised event at Westminster that he had found bankers "not nearly as bad as one hoped that they would be".
"They do not come in with horns and a tail burning £50 notes to light large cigars," he said.
The problem, he said, had been "slightly unsophisticated" errors, lending "very, very large amounts of money to people who could not pay them back".
"Those two errors alone are quite enough to bankrupt any bank."
He suggested the solution lay in reconnecting the bank with the community, and that "at least part of the banking system should be local".