Renteria collapsed and died in his Salt Lake City home Sunday as he was getting ready for church. He was 56.

The longtime community activist, known for voicing strong and often controversial opinions on a variety of issues, was unsuccessful in two mayoral races and one for the state Senate.

Close friend Lee Martinez met Renteria in the late 1970s at the University of Utah, and said he admired his passion as both became community activists. Martinez remembered when Renteria organized the community to save a Central City tree that had become a shrine when a passer-by saw a likeness of the Virgin Mary on it.

"He was always fighting for the underdog, and he always took on the unpopular causes," Martinez said. "He didn't mind hard work."

Luz Robles, now running as a Democratic candidate for Senate District 1, knew Renteria for about 10 years through community groups. She said he had a "unique voice" in the way he raised concerns and never gave up.

"He was always outspoken, and it included making [issues] very public," she said.

Controversy often swirled around the Salt Lake City native. Last summer, Renteria was ousted as president of Centro Civico Mexicano while he was in jail for three weeks after violating probation for a misdemeanor traffic offense.

He refused to step down from the nonprofit Latino agency until the board voted him out months later.

Lloyd Mondragon, who has known Renteria for more than three decades, said his best friend was a kind-hearted, charismatic guy - despite his sometimes combative reputation.

"He was misunderstood a lot," Mondragon said.

Mondragon remembered that Renteria once acknowledged that he knew he probably wouldn't win the offices he ran for. But the activist wanted to voice his opinion and encourage other west-siders to get involved in the political process. "He just wanted equality for all people," Mondragon said.

Renteria was born and reared in Salt Lake City. He graduated from Judge Memorial High School, then the University of Utah and later, the devout Catholic graduated from the law school at Brigham Young University. He never took the bar exam to practice law, but he often helped people with their legal issues, Martinez said. Renteria had several jobs throughout the years.

He played the guitar and loved boxing, Mondragon said, adding that the two friends used to go camping, play softball and golf together.

Mondragon said the last time he saw his friend was last week over lunch, when Renteria scolded him for working too much and not making time for fun. Renteria didn't say he was ill, but Mondragon said, "He sounded somewhat distressed . . . his voice just sounded different."

Friends say Renteria is survived by his son, John Michael, and daughter, Angie; four brothers; three sisters; and his father, Juan.

sanchez@sltrib.com