ATLANTA — Mayor Kasim Reed’s decision to dismiss his fire chief last week for giving co-workers copies of a Christian self-help book condemning homosexuality is fanning new kinds of legal and political flames in this city, where deeply held religious convictions exist in a kind of defining tension with a reputation for New South tolerance.

Mr. Reed fired Kelvin Cochran, the chief, on Tuesday over the distribution of his book, which condemns homosexual acts as “vile, vulgar and inappropriate.” Reached at home on Thursday, Mr. Cochran referred all questions to his lawyers, who issued a statement on his behalf.

“I am heartbroken that I will no longer be able to serve the city and the people I love as fire chief, for no reason other than my Christian faith,” Mr. Cochran said in the statement released by the Alliance Defending Freedom, an Arizona-based conservative legal organization that is representing him. “It’s ironic that the city points to tolerance and inclusion as part of its reasoning. What could be more intolerant and exclusionary than ending a public servant’s 30 years of distinguished service for his religious beliefs?”

Those sentiments are particularly weighty in Atlanta, where the legacy of the Rev. Dr. Martin Luther King Jr., a hometown hero, remains a moral guidepost for governance. As a legal matter, the spat may eventually be settled in court: Greg Scott, a spokesman for the Alliance Defending Freedom, said that the chief and his lawyers were “currently assessing legal options” that might “vindicate his right to free speech.”