The Vatican has rejected the idea that people can choose or change their genders, says a newly issued official document which also insists on procreation between women and men.
The guidance, published during LGBT Pride Month, was immediately denounced by LGBT Catholics as contributing to bigotry and violence against gay and transgender people.
Advocacy group New Ways Ministry said it would further confuse individuals questioning their gender identity or sexual orientation and at risk of self-harm.
The text, Male And Female He Created Them, was intended to help Catholic teachers, parents, students and clergy address what the Vatican’s Congregation for Catholic Education called an “educational crisis” in the field of sex education.
It called for a “path of dialogue” and listening on the issue of “gender theory” in education.
But even priestly advocates for LGBT Catholics noted that the text appeared to have relied entirely on previous papal pronouncements, Vatican documents and philosophers and theologians.
“The real-life experiences of LGBT people seem entirely absent from this document,” said Father James Martin, a Jesuit priest who wrote a book on improving Catholic Church outreach to the LGBT community, titled Building A Bridge.
”We should welcome the congregation’s call to dialogue and listening on gender, and I hope that conversation will now begin.”
Pope Francis has repeatedly argued the position that people cannot choose their genders.
But the document represents the first attempt to put the Vatican’s position, first articulated fully by Pope Benedict XVI in a 2012 speech, into a comprehensive, official text.
The document called for a new alliance among families, schools and society to offer a “positive and prudent sexual education” in Catholic schools so children learn the “full original truth of masculinity and femininity”.
It called gender fluidity a symptom of the “confused concept of freedom” and “momentary desires” that characterise post-modern culture.
It rejected terms such as “intersex” and “transgender” and said the purpose of the biological “complementarity” of the male and female sex organs was to ensure procreation.
Pope Francis recently sparked outrage, particularly among pro-choice campaigners in the US, for comparing abortions to 'hiring a hitman'.
He said: “Is it licit to throw away a life to resolve a problem?
"Is it licit to hire a hitman to resolve a problem?”
His remarks caused anger in the US - and around the world - because several states have recently moved to ban abortion and the Pope's comments appear to support those law changes.
On the gender document, Francis DeBernardo, head of New Ways Ministry, said such concepts are outdated, misinformed and ignore contemporary science on factors beyond visible genitalia that determine gender.
“Gender is also biologically determined by genetics, hormones and brain chemistry — things not visible at birth,” Mr DeBernardo said in a statement.
“People do not choose their gender, as the Vatican claims, they discover it through their lived experiences.”
He said the Catholic Church should encourage this process of discovery, saying it’s “a process by which individuals discover the wonderful way that God has created them”.