Foley memorial
A sign outside a shop remembers James Foley in his hometown of Rochester, New Hampshire August 20, 2014. REUTERS/Brian Snyder

The parents of James Foley, the American journalist executed by the Islamic State, formerly known as ISIS, said they’re trying to honor their son by resisting the urge to hate his captors and killer. Instead, they called on the militant group to spare the lives of other prisoners, including humanitarian workers.

"Jim would never want us to hate or be bitter,” Diane Foley, James’ mother, said in a press conference outside their home on Tuesday. “We’re praying for the strength to love like he did. We are praying for mercy for the remaining hostages."

“We’re just begging for mercy,” James’ father John Foley said. “They never hurt anybody. They were trying to help.”

In the video, Foley looks straight at the camera and says he wished he had more time to see his family, but that he knew it would not happen.

“The way he died was horrific," Foley's father said. "It testifies to his courage. We believe he was a martyr, a martyr for freedom."

Foley's parents had five children and his mother said her 7-year-old granddaughter Rori, Foley’s niece, told her this morning that she felt like her heart was broken.

“Sometimes as a parent it’s truly hard to know how precious and what your child is like,” she said. “We just had no idea…”

“How much he would affect the world in such a positive way,” Foley’s father added, breaking down in tears.

They urged the Obama administration to save Steven Sotloff, a freelance journalist for Time, who ISIS said it would kill next.

“I know Obama needs prayers too,” Foley’s mother said. “There’s so much pressure and so much sadness. We need to come together as a country. Please don’t criticize one another.”

President Barack Obama vowed to be “relentless” in his pursuit of the militant group that executed Foley. The White House said a U.S. Special Forces operation had been conducted earlier in the summer to rescue Foley and other U.S. citizens ISIS had kidnapped. The operation failed when no journalists were found at the target. GlobalPost, one of the many publications Foley wrote for, had hired an international investigation firm to find him when he went missing in 2012.

“No just God would stand for what they did yesterday or every single day," the president said in a news conference. "People like this ultimately fail. They fail because the future’s won by those who build and not destroy. The world is shaped by people like Jim Foley.”

Having been captured before, Foley was not blind to the dangers of war reporting. He was detained in Libya for 44 days in 2011 along with Clare Morgana Gillis, a freelance journalist; Manuel Varela, a Spanish photographer who works under the name Manu Brabo; and Anton Hammerl, a South African photographer. After his release, Foley said he saw loyalists to Muammar Gaddafi execute Hammerl.

Despite his experience in Libya, Foley returned to war reporting when the conflict began in Syria.

"I've been covering conflicts since Iraq in 2008,” he said at a fundraiser he organized to support Hammerl’s family. “I am drawn to the drama of the conflict and trying to expose the untold stories but I am drawn to the human rights side.”

In his last story for GlobalPost, Foley reported from Aleppo. In his last dispatch he told Syrian rebel Abu Sayed’s story.

“As Sayed recounted his near-death experience, he smoked a cigarette and tears welled in his eyes,” Foley wrote. “Patches of gauze were still taped to his neck.”

Foley’s father said that when friends and family asked him why Foley went back to conflict zones he would always reply, “'Why do firemen go back into a blazing home?' was his job."