Pope Benedict XVI sparked a furious reaction from other Christian groups as he also suggested that a blurring of the distinction between male and female could lead to the “self-destruction” of the human race.
The pontiff was delivering his end-of-year address to senior Vatican staff and his words were later released to the media.
The Roman Catholic Church teaches that, while homosexuality is not sinful, homosexual acts are.
It opposes gay marriage and, in October, one leading Vatican official described homosexuality as “a deviation, an irregularity, a wound”.
In his address to the Curia, the Vatican’s central administration, the Pope himself described behaviour beyond traditional heterosexual relations as “a destruction of God’s work”.
He said the Roman Catholic Church had a duty to “protect man from the destruction of himself” and urged respect for the “nature of the human being as man and woman.”
The pontiff added: “The tropical forests do deserve our protection. But man, as a creature, does not deserve any less.”
His remarks were immediately denounced as “totally irresponsible and unacceptable in any shape or form” by the Lesbian and Gay Christian Movement.
Its chief executive, the Rev Sharon Ferguson, said: “It is more the case that we need to be saved from his comments. It is comments like this that justify homophobic bullying that goes on in schools and it is comments like this that justify gay bashing.
“There are still so many instances of people being killed around the world, including in western society, purely and simply because of their sexual orientation or their gender identity.
“When you have religious leaders like that making that sort of statement then followers feel they are justified in behaving in an aggressive and violent way because they feel that they are doing God’s work in ridding the world of these people.”
The Rev Dr Giles Fraser, Vicar of Putney and president of Inclusive Church, the pro-gay Anglican movement, said: “I thought the Christmas angels said ‘Fear not’.
“Instead, the Pope is spreading fear that gay people somehow threaten the planet. And that’s just absurd.
“As always, this sort of religious homophobia will be an alibi for all those who would do gay people harm. Can’t he think of something better to say at Christmas?” Telegraph