Last week, exactly a year after finding out that my friend had gone missing in Syria, I saw him again. But it was far from the scenario his family and friends had been hoping for. Kneeling in the dirt in an orange jumpsuit, Abdul-Rahman Kassig, or Peter as he was known before his conversion, was slated for execution in the Islamic State’s latest video.

We'd braced for this moment ever since the killing of James Foley, the American journalist, in August. His executioner also threatened the life of another victim, a pattern that was followed in two videos that followed. And then, on Friday, when the group released footage of its beheading of British aid worker Alan Henning, we caught our first glimpse of Kassig since his kidnapping.

Kassig is just one of millions of innocents caught up in Syria’s war, a conflict in which disappearances and death occur every day. For him, it was an unshakable desire to help those innocents that led him to become a victim too – abducted a year ago during an aid mission.

Though some may question the risks he took, Kassig saw his calling in Syria's suffering.

I first met him at a government hospital in northern Lebanon. It was the summer of 2012 and I was working as a freelance journalist. The United Nations had just confirmed what had been obvious for some time — that the conflict in neighboring Syria was a full-blown civil war.

The wards of the Tripoli hospital were filled with horrors: A mother who had lost her entire family as well as her legs in a helicopter attack, a teenager whose spine had been shattered by sniper fire as he went to fetch bread, children peppered with shrapnel wounds. Most people see such tragedies as the sad toll of a war that they can’t influence. But Kassig couldn’t ignore the victims.

An Indiana native, he'd given up his studies back in the United States to travel to Lebanon to volunteer. He'd first worked in the country’s Palestinian refugee camps, until the tempo of the Syrian war picked up, leading him to the hospital in Tripoli.

A trained medic, he'd begun helping on the wards, changing bandages, suturing wounds. Syrians who worked with him said that when they'd gotten a call from an American asking to come and work in the hospital, they'd expected someone older to arrive, a retiree perhaps, with time and money. They were surprised when Kassig showed up, 24 years old, tirelessly dedicated.

It was the camaraderie he had with his fellow volunteers and medics, largely displaced Syrians, that struck me most when I first met him. He worked with them, slept with them, ate with them.

In the stream of do-gooders attracted by the conflict, Kassig stood out. He didn’t dabble, he lived the conflict.

In a CNN interview filmed around that time, he talked about what drove him.

"We each get one life and that's it. We get one shot at this and we don't get any do-overs, and for me, it was time to put up or shut up," he explained. "The way I saw it, I didn't have a choice. This is what I was put here to do. I guess I am just a hopeless romantic, and I am an idealist, and I believe in hopeless causes."

On the day Kassig and I met, a group of us journalists and medical workers sat in the parking lot outside the hospital, sharing stories. He talked about how he had served briefly in the U.S. military, but had come out a pacifist. It was the first of what would be many long evening chats we had on life and work.

Burhan Mousa Agha, a Syrian from the city of Homs who volunteered with him at the hospital, recently recalled a conversation he'd had with Kassig when Agha had been contemplating returning to Syria.

“He told me, ‘Brother, go back to Syria, but not to fight, because fight brings fight, blood brings blood. Go to help with humanitarian work.' "

Later, when Agha was granted political asylum in Switzerland and couldn’t afford a plane ticket, it was Kassig who stumped up the cash.

For Kassig, though, the path ultimately led to Syria. He set up an aid group, Special Emergency Response and Assistance, and moved to southern Turkey, where cross-border access was easier. It was just before a visit there a year ago that I found out he'd been kidnapped on one of his missions in Syria.

I’d tried to contact him on Facebook to tell him I'd be in town, but his account had been deactivated. He'd been missing a few days, but his family had asked for a media blackout on his case. They feared publicity could jeopardize efforts to secure his release. We hoped that the network of Syrians who loved him might be able to help secure his release, but the weeks and months passed with little sign of hope.

The media blackout remained in place until his appearance in last week’s video.

It was only then that I found out about his conversion, with his family's announcement that he'd embraced Islam during the early days of his detainment. That raised inevitable questions over the authenticity of his conversion, but a former hostage who was held with him has said Kassig found genuine comfort in his faith. Other friends say he had discussed the affinity he felt for the religion at least a year earlier, and just before he was captured, he’d fasted during Ramadan.

In his last letter to his family, which they received in June, he talked about being “at peace with my belief.”

“If I do die, I figure that at least you and I can seek refuge and comfort in knowing that I went out as a result of trying to alleviate suffering and helping those in need,” he wrote.