His church’s website maintains a running tally of “people whom God has cast into hell since you loaded this page.”

He was highly litigious and employed crude language to call attention to his cause. (The slogan “God Hates Fags” appeared on the church’s picket signs and remains in its web address.) He sued President Ronald Reagan for establishing diplomatic relations with the Vatican; denounced the Rev. Jerry Falwell, who called Mr. Phelps a “first-class nut”; and picketed the funerals of Al Gore’s father and Bill Clinton’s mother.

Mr. Phelps’s picketing began in 1991 as an outgrowth of his dissatisfaction with Topeka’s response to his complaint that gay men were using a park near his home for “indecent conduct.” His antigay effort at the park was followed by protests of funerals of people who had died of AIDS, and then multiple local churches that he criticized as tolerant of homosexuality.

In 1998, he explained his view of a wrathful God in an interview with The Houston Chronicle.

“You can’t believe the Bible without believing that God hates people,” he said. “It’s pure nonsense to say that God loves the sinner but hates the sin. He hates the sin, and he hates the sinner. He sends them to hell. Do you think he loves the people in hell?”

Later that year, he attracted global attention and condemnation when he picketed the funeral of Matthew Shepard, the gay Wyoming college student whose beating death led to a national debate over hate crimes.

It was his church’s protests of military funerals, which began in about 2005, that provoked the most widespread anger, prompting legislative bodies to establish buffer zones to limit such protests at funerals. In 2011, Mr. Phelps won a major legal victory when the Supreme Court ruled, 8 to 1, that his church’s protests were a protected form of speech. The ruling preserved the buffer zones but found that the father of a slain soldier was not entitled to damages for emotional distress caused by a protest.