"Specifically, we agree that sexual difference is real, that males and females are different in significant ways, and that a person's sex cannot change," Hasson said.
"The Church's vision of the human person differs radically from gender ideology," Hasson noted. "Christian anthropology teaches that the person is a unity of body and soul, that we are created male or female, forever."
"Gender ideology, in contrast, imagines the person as a bundle of assorted dimensions," she said, such as gender identity, gender expression, sexual orientation, and biological sex, none of which "needs to align – the person is self-determining. God is really not in the driver's seat."
Fain said she agrees that gender identity, "this idea that we have an internal sense of being male, female or neither, and that this has any effect on our material reality, is nonsense."
Dansky, whose group's primary goals are to fight violence against and exploitation of women in rape, sexual and domestic assault, and pornography and prostitution, said that her work is made nearly impossible in the context of broad social disagreement about what makes someone a woman in the first place.
"It's very difficult to solve all of those problems when we're not permitted to name the category of women," she said.
"It's very interesting to me that when our society talks about domestic violence and rape and sexual assault, and we talk about the rampant rates of these crimes being perpetrated against women and girls, everybody knows what the words 'women' and 'girls' mean."
In light of increasing acceptance of transgender ideology, the Vatican's Congregation for Catholic Education's issued a document entitled "Male and Female He Created Them" last June, explaining the Church's teaching on transgender issues and encouraging dialogue with those experiencing gender dysphoria.
The document cited the need to reaffirm "the metaphysical roots of sexual difference" to help refute "attempts to negate the male-female duality of human nature, from which the family is generated."
Such a negation "erases the vision of human beings as the fruit of an act of creation" and "creates the idea of the human person as a sort of abstraction who 'chooses for himself what his nature is to be.'"
Theories of gender, whether moderate or radical, agree that "one's gender ends up being viewed as more important than being of male or female sex," according to the document, which also reflects on the role of gender theory in education and speaks of a "crisis" in any alliance between the school and the family.
"Although ideologically-driven approaches to the delicate questions around gender proclaim their respect for diversity, they actually run the risk of viewing such differences as static realities and end up leaving them isolated and disconnected from each other," it said.
The document called for dialogue, and the protection of human and family rights. It also decried unjust discrimination and noted points of unity among people with different perspectives on gender ideology.
Looking for concrete examples of common ground, Fain told CNA that she thinks that protecting the freedom of speech of those who oppose transgenderism will be one of the most important things that radical feminists and Christians can work together for.
"(W)e need to deal with this freedom of speech issue that's happening and cancel culture, which is making most people terrified to speak out on the issue," she said.
Fain noted that when she wrote the controversial article that got her fired, she had anticipated the backlash and had been saving for months to protect herself from the blow. She recognized that most people cannot afford to lose their jobs for speaking up on this issue.
"Most people can't, and especially women who are already at a financial disadvantage are more likely to be caring for kids," she said.
"And people are terrified to speak out on this issue because of the serious economic consequences that are happening."
"And although I have many issues with the right in general, I will say that I think religious freedom and freedom of speech do go hand in hand," Faid added.
"And so the Church's work on that is probably relevant here."
Hasson identified women like Fain as "key allies" in the fight against transgenderism going forward, and said she looks forward to working with them despite differences on other issues.
"Radical feminists have been fearless in speaking the truth about sexual difference - over social media, at universities, and in public hearings. They have refused to be silenced - even after being ridiculed, 'de-platformed' at public universities, or having their Twitter accounts shut down," Hasson said.
"We differ greatly about abortion and our views of men, but I am hopeful that our work together and personal regard for each other will open up some opportunities in the future for discussions about those areas where we disagree. But for now, I'm grateful for their commitment to speak the truth, even at great personal cost."
This article is the first part of a two-part series on the Church, gender-critical feminists, and transgender ideology. Part two will be published on Feb. 12.
Mary Farrow worked as a staff writer for Catholic News Agency until 2020. She has a degree in journalism and English education from the University of Nebraska-Lincoln.