Canberra's Anglican leader, Stuart Robinson, says the detention of asylum-seeker children is damaging them.
A senior Anglican cleric says the government appears to be ignoring the damage done to children by offshore detention while rightly pursuing churches and other institutions over historical abuse.
Anglican Bishop of Canberra-Goulburn Stuart Robinson will make the comment in his address to his diocese's annual "parliament", or synod, in Goulburn on Friday.
Many people felt disillusioned as the federal government rightly pursued institutions for their historical indifference to child abuse while appearing less than cognisant of the damage mandatory offshore detention does to asylum seekers, "especially to little ones", he will say.
Bishop Robinson says an immigration psychiatrist had likened the treatment of children in detention to torture.
He said the royal commission into child abuse has served as a "wake-up call" to churches everywhere.
The Canberra-Goulburn diocese had received a request from the royal commission for files and notes from the past five decades.
At the same time, help is being provided to abuse survivors.
"This tragic aspect of our past informs every moment of our present and it will shape and influence our future," the bishop said.
"I give approximately one-third of my week to dealing with such matters."
When he was writing the speech, the bishop took a phone call from a man aged in his 60s who was sexually abused by a Sunday School teacher when he was four or five.
"He said that my belief in his story over the phone brought enormous relief and a measure of freedom.
"Yet, it is just a beginning for this fellow, and so many like him, because the damage is deep, and oftentimes generational, with whole families affected."
Bishop Robinson said it was likely the cost of ministering to survivors would rise over time because people needed to be compensated appropriately and provided with counselling.
The Canberra-Goulburn diocese held a series of Lamentation Sunday services in August, in which an apology was read and survivors were able to tell their stories.
The synod, which runs from Friday to Sunday, will debate the treatment of asylum seekers as well as a new method of selecting a bishop.