“We want to tell people they are not alone,” said Terry McDonald, the chairman of Metroplex Atheists, part of the Dallas-Fort Worth Coalition of Reason, which paid for the atheist ads. “People don’t realize there are other atheists. All you hear around here is, ‘Where do you go to church?’ ”

But the reaction from believers has been harsher than anyone in the nonbeliever’s club expected. Some ministers organized a boycott of the buses, with limited success. Other clergy members are pressing the Fort Worth Transportation Authority to ban all religious advertising on public buses. And a group of local businessmen paid for the van with the Christian message to follow the atheist-messaged buses around town.

“We just wanted to reach out to them and let them know about God’s love,” said Heath Hill, president of the media company that owns the van and one of the businessmen who arranged for the Christian ads. “We have gotten some pretty nasty e-mails and phone calls from atheists. But it’s really just about the love of God.”…

“I’m not against them getting their message out,” said the Rev. Julius L. Jackson, pastor at Macedonia Missionary Baptist Church. “I just don’t think it should be on public transportation.”