"God created man and woman; God created the world like this and we are doing the exact opposite," he said, calling the notion than children can determine their biological sex for themselves "terrible."
The influential institutions backing this are exploiting God's creation, he went on to say, and the problem is a global one.
"We are living at a time when humankind as the image of God is being annihilated," the pope continued, connecting the abuse of the natural world with the abuse of human beings. He suggested that both stem from a "lack of appreciation of humankind's God-given dignity," as the Catholic Herald reported.
"There are absolutely no grounds for considering homosexual unions to be in any way similar or even remotely analogous to God's plan for marriagend family," the paper read.
Likewise, in his papal encyclical Laudato Si, which was published in June 2015, the pope connected "gender theory" with economic exploitation.
Although the encyclical focused on the threat of climate change and environmental degradation, Francis also wrote critically in the document of the desire to "cancel out sexual difference," noting that "thinking we enjoy absolute power over our own bodies turns, often subtly, into thinking that we enjoy absolute power over creation."