Father David O’Hearn spent eight years fighting the men he sexually abused as vulnerable young boys in the 1980s and 1990s. On Monday some of them will be in a Sydney court to watch him pay the price.

They will pay for the rest of their lives, the men said in victim impact statements.

“We will never know what it's like to live a normal life as we had that opportunity taken away from us as young boys,” said one of O’Hearn’s victims.

“I think my life could have been totally different if the abuse had never occurred. I would be a different person but I will never know what that person would have been like. I know that I can't blame everything in my life on the abuse but I do know it's had a significant impact on me.”

O’Hearn was first charged with child sex offences in 2008, against boys as young as nine in the Hunter region in the 1980s and 1990s.

Several juries found him guilty of all charges before them, but O’Hearn appealed and won the right to further trials. He sought leave to appeal to the High Court to have separate trials on some of the matters and was partially successful. He was eventually found guilty of more than 40 offences against six boys.

O’Hearn’s denial of all charges and lack of remorse had taken its toll, his victims said.

“The two and a half year process to get to court was emotionally draining and the worry of being scrutinised once the matter reached trial was also very hard to cope with,” said one of his victims.

O’Hearn was the master manipulator who charmed and groomed people to get his way and told child victims to “look up at Jesus” pictures as he sexually abused them in church buildings.

A third victim said the offences against him had been “locked away in my memory” and took 26 years to disclose. It had been “26 years of questioning myself as to my own identity”.

A fourth victim said O’Hearn’s sentence “will be nothing to me, as I have been handed a life sentence because of what he’s done”.

 A fifth victim said he struggled while watching O’Hearn acting like a priest, and knowing his dark secret.