Archbishop Salvatore Cordileone of San Francisco has criticized gender transitions as threatening the foundation of the church's faith.

“The clear biological fact is that a human being is born either male or female,” Cordileone told a Sacra Liturgia conference audience in New York.

“Yet now we have the idea gaining acceptance that biological sex and one's personal gender identity can be at variance with each other, with more and more gender identities being invented.”

Cordileone, who spearheads the U.S. Conference of Catholic Bishops' (USCCB) opposition to marriage equality, made his comments just three days after Caitlyn Jenner – now the most famous transgender woman in America – made her debut on the cover of Vanity Fair.

While he did not mention Jenner by name, it would be nearly impossible to say that his comments weren't directed at the growing interest – now at high boil with Jenner's cover – in gender identity.

“Gender ideology,” Cordileone said, poses a threat to society and to the faith.

“That is because God has used marriage as the primary sacred sign of our relationship with him,” he explained.

“It's all the story of a marriage. God's marriage covenant with Israel is fulfilled in the blood of Christ on the cross, establishing the new and eternal covenant between him, the bridegroom, and his bride, the church.”

“When the culture can no longer comprehend those natural truths, then the very foundation of our teaching evaporates and nothing we have to offer will make sense,” he said.