"As an atheist who challenged America's deeply held religious convictions, he will continue to serve as a thorn in the side of those who believe that religion requires no rational defense," Rabbi Shmuley Boteach, a friend and frequent sparring partner, wrote in a tribute for The Forward, a national Jewish newspaper.
Hitchens had long been a foe of organized religion and its leading lights; when the late Pope John Paul II beatified Mother Teresa in 2003, Hitchens dismissed her as a "fanatic, a fundamentalist and a fraud." He called the late Jerry Falwell an "ugly little charlatan," saying "it's a pity there isn't a hell for him to go to."
Throughout his career, Hitchens rejected religious faith as "evil nonsense" and a "real danger" to civilized society. "I regard it as an enemy," he said in 2008, "and a real deadly one."
The self-described anti-theist channeled his unbelief into a direct and eloquent challenge of religion, especially the large and small actions carried out in God's name.
"Christopher Hitchens changed the discussion about religion and nonbelief by championing public criticism of theology," said Roy Speckhardt, executive director of the American Humanist Association.
The murderous religious extremism behind the 9/11 terrorist attacks crystallized Hitchens' fears about religion. In the years after 9/11, he and other public atheists shot to the top of best-seller lists with titles like his 2007 manifesto, God Is Not Great: How Religion Poisons Everything.
Together with Sam Harris, Richard Dawkins and Daniel Dennett, Hitchens was hailed as one of the "Four Horsemen." In a tweet after Hitchens' death, Dawkins heralded his friend as a "valiant fighter against all tyrants, including God."
Still, Hitchens' take-no-prisoners style was not universally embraced within atheist circles. Hitchens could be as militant and fundamentalist as those he criticized, his atheist allies said, and did little to help the movement's public perception.
"Now, they're very good atheists and very dedicated people who do not believe in God," Paul Kurtz, founder of the Council for Secular Humanism, told NPR in 2009. "But you have this aggressive and militant phase of atheism, and that does more damage than good."
When Hitchens announced his terminal cancer last year, some foes hoped it would prompt a deathbed conversion of sorts. Hitchens said he was grateful that people would care enough to pray for him, but swiftly rejected the idea that death could or should make him a believer.
"I have resented the idea that it should be assumed, now that you may be terrified, or depressed, that now would be the time to throw out values you have had for a lifetime," he said. "Repulsive. Wholly contemptible."
In life, Hitchens swam against the tides of religious belief that shape so much of modern life. In death an irony that would delight and disturb his contrarian soul believers are using the loss of the most articulate voice of unbelief in a generation to argue, once again, for belief.
"The point about Christopher Hitchens is not that he died of unbelief," tweeted R. Albert Mohler, president of Southern Baptist Theological Seminary, "but that his unbelief is all that matters now. Unspeakably sad."