About 20,000 atheists gathered within shouting distance of the Washington Monument on Saturday for a Reason Rally hell-bent on damning religion and mocking beliefs.

FOLLOW:Faith & Reason blog on Twitter

A full pantheon of demigods of unbelief -- British scientist and full-time atheism rabble-rouser Richard Dawkins was the headliner -- kept a crowd of all ages on their feet for more than six hours (and counting -- I left before the band Bad Religion was set to play).

Dawkins didn't appear until five hours into the event, but few seemed discouraged by the near-constant rain or drizzle. They whistled and cheered for his familiar lines such as:

I don't despise religious people. I despise what they stand for ... Evolution is not just true, it's beautiful ...

Then Dawkins got to the part where he calls on the crowd not only to challenge religious people but to "ridicule and show contempt" for their doctrines and sacraments, including the Eucharist, which Catholics believe becomes the body of Christ during Mass.

That was a step further than Craig Lowery, a Dawkins fan, said he's willing to go. Lowery, of Washington, D.C., applauded but admitted he's not a confrontational atheist, saying:

I might make fun of them in my head but I wouldn't say it. Most people, religious or otherwise, are good people.

Outrage was the parlance of the day, however, for many speakers, including David Silverman, Reason Rally organizer and American Atheists president.

He reveled in the group's reputation as the marines of atheism, as the people who storm the faith barricades and bring "unpopular but necessary" lawsuits.

Silverman may have gone a bit further in his rhetoric than he intended. In a thundering call for "zero tolerance" for anyone who disagrees with or insults atheism, Silverman proclaimed, "Stand your ground!"

Unfortunately, of course, the phrase "stand your ground" is in the news this week as the legal cover for the killing of Trayvon Martin in Sanford, Fla., last week. Under Florida's "stand your ground" law, George Zimmerman could claim he feared Trayvon, a teen armed with iced tea and Skittles, would harm him.

Silverman meant a verbal, not a literal, call to arms here. Still, the line didn't draw applause as his other take-no-insults charges did.

Several of the featured names were famous folks who sent in videos: Penn Jillette, Bill Maher and U.S. Rep. Pete Stark. Others, popular in the Internet niche of skeptics, free-thinkers and atheists, came to the microphone to address the soggy crowds in person. A sampling:

Friendly atheist blogger Hemant Mehta urged people to run for office, any post from school board to Congress to dogcatcher.

Greta Christina, author of Why Are You Atheists So Angry?, attacked every major faith, even the teachings of the Dalai Lama. In a long litany of what makes her angry, she got all the way back to Galileo (overlooking the modern Catholic Church's restoration of his reputation).

Adam Savage, co-host of Mythbusters on the Discovery Channel, said there really is someone who loves and protects him and watches over his actions -- "It's me!"

Many were surprised to learn that Fred Phelps, head of Westboro Baptist Church -- famous for its anti-gay signs at the funerals of innocent people -- has an atheist son, Nate. Nate drew big applause for denouncing the fundamentalist faith of his family.

Meanwhile, 12 men with big signs warning Jesus demands repentance ignored the official holding pen fenced off for counterdemonstrators. Instead, they stood on the grass about 100 yards from the podium, each surrounded by a knot of eager-to-argue unbelievers.

Pastor Larry McCune, of Parkersburg, W.Va., found a thoughtful listener in Liam Shane, 18, of Leesport, Pa., who describes himself as "just in this world trying to figure things out as I go."

Because every rally seems to include a family that brought their tots to hear "the truth" -- religious or otherwise (The Washington Post had a sweet picture from the Religious Liberty rally in D.C. on Friday), I chatted up one of the many families at this event.

Michelle and Joshua Gajewski brought Mark, 2, and Amity, 7, with them from Richmond, Va., to "be with people who share our views," Michelle said. Joshua said they're the only out atheists in their families.

On Saturday, many parents might be getting the news -- "Hi, Mom, I'm an atheist" was a popular sign.

Organized by a coalition of godless groups led by the American Atheists, along with secularists, humanists and niche groups (students, blacks, Jews, etc. ), the American Atheists hold an annual convention in the Washington suburb of Bethesda on Sunday. The theme: "Come out, come out, wherever you are!

That's not easy, said Rebecca Cunningham of Fredericksburg, Va. When she changed her status on Facebook to atheist, she lost 34 "friends."