(CNN) Pope Francis bluntly criticized Catholic bishops in the US for their approach to the church's sexual abuse crisis, saying that their finger-pointing, abuses of power and "playing the victim or the scold" have undermined the church's credibility.

"The church's credibility has been seriously undercut and diminished by these sins and crimes," the Pope said of the abuse of children by Catholic clergy, "but even more by the efforts made to deny or conceal them."

Francis also said the bishops' disunity and blame-shifting have led to mistrust and pain among the church's followers.

"God's faithful people and the Church's mission continue to suffer greatly as a result of abuses of power and conscience and sexual abuse, and the poor way that they were handled, as well as the pain of seeing an episcopate (body of bishops) lacking in unity and concentrated more on pointing fingers than than on seeking paths of reconciliation."

The Pope's eight-page letter to the American bishops is a mix of spiritual encouragement and blunt criticism. He urges the bishops to root their response to the abuse crisis in Scripture, and makes clear that their actions thus far have been far from ideal.