Child abusers used the Anglican Church as a "safe haven" because their activities would not be monitored and they would be offered "cheap forgiveness", a royal commission has heard.

The Anglican Archbishop of Sydney, Glenn Davies, has told the Royal Commission into Institutional Responses to Child Sexual Abuse that laypeople were the main perpetrators of abuse.

He said that in the past, offenders were given access to youth groups and other church-run organisations too easily.

"Perpetrators or potential perpetrators seek a safe haven where their activities will not be monitored," Dr Davies said.

"Inadequate screening of our laypeople in past years allowed people with corrupt motives to abuse young boys, in particular, but also girls."

He said complaints were made against 17 clergy since the 1960s, and were sustained in four cases.

Church offered 'cheap forgiveness'

Dr Davies also said children were put at risk because of the abuse of power and the Christian concept of forgiveness.

"I was also enraged at the way in which my church mishandles and, in a sense, further traumatised the survivors of abuse in the way in which they were not believed and the way in which no proper action was taken," he said.

"Forgiveness is corrupted when there's no restitution, when there's no true repentance.

"I think what's happened in the past is there's been easy forgiveness ... cheap forgiveness, whereby a person has been forgiven, thinking 'it's not going to happen again'."

"We too easily forgave.

"I think at heart, people almost didn't believe this type of behaviour could be engaged in, in a church environment.

"And that's why we didn't listen properly to children. And when complaints were made they were not properly addressed."