An LGBT rights campaign specifically targeting Christians has been launched in Mississippi, sparking anger from church leaders.

Under the banner 'All God's Children', an ad is being run by the Human Rights Campaign (HRC) which encourages churches to welcome gay people.

It features a 61-year-old self-described "Bible-believing born-again Christian", Mary Jane Kennedy, who tells the story of her son coming out as gay.

"Nothing in my life had every prepared for that. I said, 'What's going to happen? This is going to tear our family apart. Your daddy will die.' It's hard to talk to somebody and tell them something that's going to break their heart. And it was the first time in my life that I've seen him cry," Kennedy says in the clip.

"One of the main things that I want to happen, is to open the arms of Jesus Christ to people that have been pressed out of the church; we've closed our doors to people who need us the most.

"God calls us to love each other."

A statement on the All God's Children segment of the HRC website says: "We are Mississippians. We live here. We work here. We go to church here. Have children here. Pay taxes here. We serve in the Armed Forces. We volunteer in our communities. We are your neighbors, co-workers, friends and family.

"We are young and old, men and women. We are all God's children. It is only for God to judge, not us. We need to treat everyone with respect."

The testimonies of four more Mississippians will be aired on local television in the coming weeks, including that of a state legislator, an openly gay Iraq War veteran, a transgender student and a church pastor.

The campaign is a result of extensive research into how best to engage southerners and people of faith with LGBT equality. HRC Mississippi Director Rob Hill, a former United Methodist minister, said on Thursday that a call to encourage people from all over the state to get behind the campaign has been recieved well. 

"More than four thousand Mississippians from all across the state joined our conversation, and their response to our work and this campaign was tremendously positive," he said.

"We feel truly blessed so many folks opened their hearts to us, and we're very encouraged to continue to share our message that we're all God's children, and that everyone in Mississippi should be treated with dignity and respect."

"We are promoting tolerance, mutual respect, and are asking Mississippians to keep an open mind about LGBT people," Hill added. "We're all God's children...It was He [Jesus] who taught us that we should treat others as we wished to be treated."

However, the campaign has been denounced by some church leaders in the region.

"There is an inherent rejection of the Gospel when we do not affirm [the] biblical [vision of] human sexuality, especially as it's portrayed in marriage because marriage is the greatest illustration that God has given us of Himself and how He loves the church," Chas Rowland, pastor of Bovina Baptist Church in Vicksburg, told the Baptist Press.

"There is no doubt where Mississippi Baptists stand. [We] affirm biblical marriage."

Rowland encouraged Christians to "stand up and speak the truth". "People's souls are more important than political correctness. We've just got to have some courage," he said.

The American Family Association (AFA), a conservative Christian group, has denounced the campaign as a "war against the Bible in America".

"HRC is spending hundreds of thousands of dollars in outside monies to undermine what Scripture teaches and to insult, denigrate and target those who hold to Scripture. For an organization that claims tolerance, HRC employs deceptive tactics and outright lies to attack those who respectfully disagree with them. This is hardly tolerance," AFA President Tim Wildmon said in a statement.

"AFA will not be fooled by this campaign to normalize homosexuality in the southern states, and we hope others won't be fooled either. The ads are deceptive and meant to mislead. It's never OK to bully, harass or physically assault homosexual individuals. These ads tell outright lies claiming Bible-believers favor such hateful and violent practices. When you have to lie to make your case, it's a clear indication your case is devoid of truth."

According to a recent Gallup poll, Mississippi is the most religious state in America, and an estimated 55 per cent of its population is Baptist. 22 per cent of LGBT Mississippians reported having experienced harassment at their house of worship at least every month.

The state's Baptist Convention adopted two resolutions defending marriage as the "lifelong union of one man and one woman" and opposing "all efforts by any governing official or body to validate transgender identity as morally praiseworthy" in October.