The family of executed US journalist James Foley said they were prepared to forgive the British terrorist who beheaded him.
Showing astonishing courage, dad John pledged that one day they would feel able to absolve the Islamic State fanatic known as Jihadi John.
He told millions on American TV: “Not today… but as Christians we have to."
And he revealed his family had watched the gruesome video of his son’s death.
“We just needed to know," he said.
In the same interview James’s sister Katie implored her brother’s killer, who spoke with an East London accent on a video of the execution, to stop the bloodshed.
The 26-year-old naval nurse said: “We are all just praying that he and other captors can be merciful."
IS, holding 20 Westerners, paraded fellow US hostage Steve Sotloff, 31, at the end of their sickening video and said he would be killed next.
Katie also spoke of the support the family had received from around the world and recounted a tribute made by one of former teacher James’s ex-students.
She said: “He was talking about Jim coming in to his life at a pivotal moment.
“He said if the gentleman that killed Jim had a Mr Foley in his life to nurture and teach him, maybe it would have been different."
Speaking from the family home in Rochester, New Hampshire, Katie revealed Pope Francis had called them to say her brother’s death was an act of martyrdom.
Brother Michael, 30, then revealed the family had spoken to several parents whose children had joined IS, which is bringing death to swathes of Iraq and Syria.
He said it came as no surprise “Jihadi John" was British, and added: “There are hordes of Europeans over there.
“We have even spoken to parents of children who have fled, so it wasn’t surprising."
There are an estimated 12,000 IS terrorists fighting on Western passports with 500 from the UK and up to 100 from the US.
Michael expressed frustration at the handling of the crisis by the US.
The White House refused to pay a ransom for James, 40, and other US captives when the kidnappers demanded a “ridiculous" £80million.
He pointed out that France and Spain had managed to secure the release of their citizens after paying cash through intermediaries.
He said: “I really, really hope Jim’s death pushes us to take anther look at our approach to terrorist and hostage negotiation.
“I just feel strongly that more can be done."
Michael then appeared to question if a failed attempt to rescue the hostages on July 4 ever took place.
“I’d like to think it did happen but I certainly wasn’t aware of it," he said.
US officials said special forces managed to sneak undetected into an IS camp in search of James and up to 20 Western hostages but were forced to withdraw when they discovered they had been moved.
The journalist was covering the Syrian conflict when he was kidnapped two years ago on the Syria-Turkey border.
Michael said he hoped President Obama would do more on behalf of US hostage Steve, including considering trading Guantanamo Bay prisoners.
The family revealed that last week IS sent them a chilling email threatening their son would die to pay for US attacks on their forces.
Dad John said they had six earlier emails, bringing hope they could still negotiate his release.
They knew they could not raise the full ransom but had hoped the £3million they had gathered might be sufficient.