Mayor of Atlanta Kasim Reed has been accused of being the "Antichrist", "anti-Christian" and a "Muslim" since he made the decision to sack Atlanta fire chief Kelvin Cochran.

He's responded to the criticism by saying that he is a "man of deep faith" but Cochran violated the city's standards of conducts.

Cochran self-published a 162-page book last year entitled Who Told You That You Are Naked?, aimed at helping men overcome feelings of guilt over past sins. It defines 'uncleanness' as the "opposite of purity; including sodomy, homosexuality, lesbianism, pederasty, bestiality, and all other forms of sexual perversion". It discusses homosexuality in half a page, but describes it as "vile, vulgar an inappropriate".

He was suspended for a month in November and fired on 6 January.

Cochran and his supporters say he has been targeted for his Christian faith and a number of prominent Christian groups have backed his cause, including the Family Research Council and the Billy Graham Evangelistic Association.

This week hundreds gathered in the Georgia State Capital in a 'Standing for our Faith' rally and there have been calls for a reconsideration of proposed religious freedom legislation in the state.

But what actually happened both before and after the book was published is somewhat disputed.

Reed said that it was a question of Cochran's judgement and not his faith that cost him his job. He says Cochran failed to ask permission to refer to himself as Atlanta's fire chief in the book, which could have led people to think that the city supported his views. Cochran denies the claims and says he did seek permission for the book.

The mayor has also said that Cochran should not have distributed the book to colleagues as it would suggest discrimination against homosexuals among city employees.

In a letter distributed by the Atlanta Journal-Constitution earlier this week Reed said: "While you may have read articles that asserted the issue at hand was Chief Cochran's religious beliefs, I can assure you that those comments could not be further from the truth.

"The truth is that I am a man of deep faith myself, and we are a city of laws. Chief Cochran's book, 'Who Told You You Were Naked,' was published in violation of the city's Standards of Conduct, which required prior approval from the Board of Ethics. I believe his actions, decisions, and lack of judgment undermined his ability to effectively manage a large, diverse workforce. Every single City of Atlanta employee deserves the certainty that he or she is a valued member of the team and that fairness and respect guide our employment decisions. His actions and his statements during the investigation and his suspension eroded my confidence in his ability to serve as a member of my senior leadership team."

Speaking to MSNBC news on Thursday, Reed said: "I hired him, at the end of the day, to put out and prevent fires not to be at the centre of one... and the fact that I'm on your show right now is precisely the reason that we require people to get permission before publishing books."

But since the decision Reed has received a large number of emails from fervent Christians, many of which have been unpleasant.

"If you read the emails, the comments are way out of bounds. They've gone way beyond a normal conversation," he said in an interview with local news station WXIA.

"Now I ran for office and I got elected to this job. I certainly take my share of criticism and heat, but I've got a wife and daughter at home. I have crazy people calling my house, hanging up the phone, calling me the Antichrist, saying I'm some form of Muslim. And while I respect Muslims and other faiths, I'm not [a Muslim] and these people are just taking it a bit too far."

The campaign against Reed's decision has received high profile support. Franklin Graham encouraged Christians to attend Tuesday's rally and said on Twitter that it would "send a [message] to those who would discriminate against believers".

Fox News presenter Todd Starnes told his 48,800 followers to "Send a message to Atlanta City Hall and their anti-Christian mayor" with a link to the petition set up by the Georgia Baptist Convention.

However, Reed has also received considerable support for his decision, both on social media, and in an editorial in the New York Times published on Tuesday.

The editorial board maintained that Cochran's comments were inappropriate for someone responsible for a "large and diverse work force". They added that his religious freedom was guaranteed by the First Amendment but that did not permit him to "foist his religious views on other city employees".