Buckner lived in metro Atlanta for 31 years before moving to Buffalo, N.Y., in January to head the national atheists' group.
The son of an Episcopal priest, he began to question the faith in high school and college. Not believing in God is a mixed blessing right now, he said.
"If you are religious, and believe there is an afterlife and an overall purpose to life, that might bring some comfort," he said. "But as an atheist, I don't have any overarching concerns about how God could let things happen."
Judy Thompson, president of the Atlanta Freethought Society, said she finds irony in what she sees as a push for religion right now.
"It seems to me religious extremism is the problem," she said. "That's the cause for this terrorism."
Thompson said she was never a believer and feels no religious impulse in response to current events.
"I think people who have religious beliefs would tend to rely on them in traumatic times," she said, "but if you don't have religious beliefs, trauma doesn't cause them to suddenly spring up in your head."
The invocation of God is "meaningless," said Reginald Finley of Atlanta, who hosts an online atheist radio show called "Live with the Infidel Guy" (www.atheistnetwork.com). "What do we really mean?" he said. "Which God is the president talking about when he says 'God bless America'? Everyone interprets their god in ways that suit how they want to live."
Finley, who attended Methodist and Baptist churches as a child, took a course on atheism at St. Leo College Center at Fort McPherson "to see what these heathens were up to."
Now, he said, he does not believe there is a god, "as most people don't believe in Santa Claus or pink unicorns."
"If people need their god belief to get through their pain, so be it," Finley said. "The biggest difficulty I have is when people in the political arena who have fundamentalist beliefs try to change laws to suit their fundamentalist belief systems. We can look at Afghanistan and see that doesn't work."