Desmond Tutu has said he would rather go to hell than worship a homophobic God.
The Nobel peace laureate and anti-apartheid hero was lending his support to a UN-backed campaign for gay rights in his native South Africa.
Though same sex marriages are legal in the country, homosexuals still experience brutal violence. Last month a lesbian was found dead, having been sexually assaulted with a toilet brush.
The retired former Archbishop of Cape Town, 81, is a long-standing campaigner for gay rights, and compared the struggle to that for racial equality in South Africa.
He said: "I would refuse to go to a homophobic heaven. No, I would say sorry, I mean I would much rather go to the other place.
"I would not worship a God who is homophobic and that is how deeply I feel about this.
"I am as passionate about this campaign as I ever was about apartheid. For me, it is at the same level."
Same-sex relationships are illegal in more than a third of countries around the world and punishable by death in five, said UN human rights chief Navi Pillay, who also spoke at the launch of the Free and Equal campaign in Cape Town.
According to the rights group Amnesty International, homosexual acts are still a crime in 38 African countries.
According to AFP, Ms Pillay said: "People are literally paying for their love with their lives.
"I constantly hear governments tell me, 'but this is our culture, our tradition and we can't change it'... So we have lots of work to do."