Last Christmas, Ruben Rivera slept in the backseat of his father's pickup truck in Kensington with nothing to keep him warm but the heroin in his pocket.

If his father had found him tucked away in his truck in the Christmastime cold, Ruben does not think he would have invited him inside. That goodwill had long ago disappeared. Ruben doesn't blame him.

By last Christmas, Ruben, 55, had been living on the streets of Philadelphia for eight years. He had been living on heroin for much longer. He had lost three brothers and a sister to addiction. He wanted to join them.

He doesn't remember if that night in his father's truck, he even knew it was Christmas.

"When you're homeless and you ain't got nothing, you don't think about Christmas," Ruben said. "Christmas don't mean nothing."

Ruben had started using heroin as a teenager in Brooklyn, where he lived with his mother and eight siblings.

Along the way, he did eight years in prison for dealing. He lost a marriage and a drywall business. He was not a father to his children.

In recent years, he no longer saw his ailing mother - who had always been there for him - because he was high. He tried to hang himself in an abandoned house near Fourth and Lehigh, but the electrical cord he was using snapped.

For a time, he carried a 9mm pistol, but, unable to find the courage to use it on himself, he would sometimes goad dealers into fights, hoping they would do it for him. One of those dealers beat him with a length of pipe, breaking his shoulder, wrist, and arm.

Most nights Ruben slept in Lehigh Park. When he could, he slept in his father's truck, slipping in through the rear window, shivering through the cold.

He doesn't know how he survived.

After last year's cruel winter, he decided he wanted to live.

In February, he allowed an outreach worker to take him to detox. After 33 days in rehab, Ruben arrived at St. Elizabeth's Recovery Residence in North Philadelphia, one of Sister Mary Scullion's Project HOME facilities.

Project HOME program manager Alexis Pugh can laugh now when recalling the Ruben she first met. How he "kicked and screamed" over St. Elizabeth's regimented schedule.

But Pugh watched as Ruben muscled through those first few months. How he began to adapt. How hard he worked.

"I saw drive and determination," she said.

In September, Ruben jumped on Pugh's offer of a spot in Project HOME'S resident apprentice program, which teaches job and life skills and offers a paying internship.

Ruben went to work as a janitor at Project HOME's JBJ Soul Homes on Fairmount Avenue, permanent housing for people trying to escape homelessness. Seven hours a day, four days a week. He excelled at it, listening to his R&B on his earplugs as he swept the halls and mopped the floors.

In October, when Ruben's mother died, Pugh and other staff members worried that Ruben would not come back after the funeral. That he would relapse.

But he did come back. He came back clean and went back to work.

On Friday, Project HOME offered Ruben a permanent position. He accepted.

On Monday, he talked about his Christmas plans. How he will spend this Christmas delivering presents he and other residents bought for a family in need in the community. How he will celebrate this Christmas with his new friends and coworkers. How far he has come.

"I feel proud," he said.

And he spoke of the gift those at Project HOME had given him - one of the greatest gifts anyone can give. They saw him not for what he was, but for what he could become.

Merry Christmas, Ruben.

mnewall@phillynews.com 215-854-2759 @MikeNewall