Aoife Assumpta Hart calls herself a “nunnabe” – somebody whose dream is to be a nun. She has wanted to enter religious life since she was eight. But, she says, it can’t happen, for a simple reason.

Hart is a transsexual, and although she now identifies as female, she was born male. “Nuns are communities of females,” she says. However much she yearns to be a nun, that doesn’t prove it’s her vocation: it is a “thwarted calling”.

“Speaking honestly,” Hart goes on, “celibacy seems to be the vocation of trans people: we are not eligible for holy orders or the religious life, and marriage – according to the principles firmly established in 20th-century moral theology – is simply not something we can fulfil in a way the Catechism requires.”

If life is complicated for trans people, it is perhaps even more so for trans Catholics. Hart describes her transsexuality quite bluntly: it is “a rare, terrifying and life-threatening disorder”, she says, in which the body and the mind are out of kilter. In her case the necessary treatment was “a supervised transition” involving “hormones and surgery”. She is sometimes told that she hasn’t confronted the “truth” of her situation. ‘‘I am, on the contrary, confronting it directly,” she says.

“I am not female nor ever will be. I am a simulation of the female form.”

Nevertheless, she says her transition “has brought me profound mental relief”. And it has helped her faith: “I am able to love myself, and thereby love my Lord exponentially more.”

Hart does not speak for every trans Catholic. There are many opinions about trans people’s identity and possible vocations – and little has been officially taught on this subject. What is uncontroversial is that the Church could do better at making space for trans people. “Right now,” Hart observes, “the debate seems to be ‘everything goes’or ‘nothing goes’.”

While some are entirely permissive, others are hostile to trans people: there are even stories of priests asking them to stay away from church. Hart hopes that a middle ground might emerge – “a balance between good theology and treating people compassionately”.

For some Catholics, no compromise is possible. Don’t trans people deny that God created us male and female? Don’t they epitomise the sad philosophy that one’s feelings define one’s identity? And aren’t they at the vanguard of a political movement which seeks to overturn precious social institutions, and which often seems to have Christians in its sights?

I asked Anna Magdalena, a trans woman who writes the Catholic Transgender blog (catholictrans.wordpress.com), about the anxiety many Christians feel when it comes to trans issues. “A lot of the anxiety is valid,” she says: there is “a radical ideological movement” which ruthlessly advances its agenda. At the heart of this movement is the notion that male and female are nothing more than socially constructed categories.

That view, plainly, is incompatible with Catholicism; but then, it is not held by all trans people. On other questions – on the experience of transsexuality, on gender transition as a treatment – the Church has yet to say very much. “There is practically no teaching on transgenderism in the Church,” says Mgr Keith Barltrop, who is Cardinal Nichols’s personal liaison with the Westminster LGBT Catholics group.

Theologically, Mgr Barltrop goes on, “the Church is bound to proceed with caution”. But so far little has been said. “What popes John Paul, Benedict and Francis have said clearly is that the Church cannot accept fashionable current theories on the essential fluidity of gender. This should be obvious in the light of Genesis 1:27 – “God created man in the image of himself … male and female he created them.”

The Christian backlash, says Anna Magdalena, would be legitimate if it simply opposed this radical ideology. There is room for scepticism: “I have met people who said they were transgender and I was like, there’s something else going on here.” Sometimes attention-seeking seems to lie behind such statements, she observes; sometimes it appears to be a political act.

“So there’s all this stuff muddying the waters,” she says. “Behind that, though, there are concrete people, real experiences. People wake up that way, you know. And there’s this feeling, it seems, among a lot of Catholics, that everything a transgender person is doing is a lie. That everything is artifice, that even the most authentic narratives are being twisted, are being manipulated in order to tug at people’s heartstrings. This is a very easy way to write people off.”

One common assumption among Christians is that trans people are prioritising subjective feelings over objective truth. Someone who experiences transgender feelings, writes one Catholic blogger, should learn “to fully accept himself as God made him to attain peace”. These confident assurances sound rather insubstantial next to the personal story Anna has told on The Transgender Catholic:

“I tried everything in my power to push that part of my soul down for good. I had to change myself! I did everything in my power to ’embrace my masculinity’. I became a Teddy Roosevelt-inspired, weightlifting, protein-guzzling, dapper-dan-wearing, swing-dancing, dirt-loving, super-heterosexual philosopher bro.

“I did everything I could to do exactly what people would expect would fix my ‘problem’: not only did I embrace my masculinity, but I channelled my feminine side, playing the ‘sensitive guy’card for all it was worth. But I never succeeded at doing anything other than method act.”

Looking back, Anna writes, she was“shutting down my heart more and more until I could barely feel anything”.

For her, as for Aoife Assumpta Hart, it was a gender transition which brought her back to mental health. Some Catholics have argued that transitioning is forbidden by the Catechism’s teaching against mutilation. (Paragraph 2297 says: “Except when performed for strictly therapeutic medical reasons, directly intended amputations, mutilations and sterilisations performed on innocent persons are against the moral law.”) But others underline the exception for “therapeutic medical reasons”, and argue that surgery helps many trans people to go on living.

The Spanish Cardinal Urbano Navarrete Cortés argued that gender transition surgery might be permissible to “free the patient from an intolerable psychological conflict”.

Catholic online evangelist Bishop Robert Barron sees the former Olympian, now TV reality star Bruce Jenner’s transformation into Caitlyn Jenner as sheer Gnosticism, in which “the body is presented as an antagonist which can and should be manipulated by the authentic self”. Anna, a Barron fan, disagrees.

“I cannot speak for all transgender people on earth,” she says, “but my personal experience has validated a Catholic understanding of the relationship of the body and the soul.” Before her transition, she recalls, “I had a reality that maybe you would call Gnostic: I felt like a brain in a vat. It wasn’t a matter of belief, it was a matter of experience.

And then post-transitioning, I have a very Catholic experience of my body. So I’d say that is a story of redemption, a story of integration.”

For Anna, “the Catholic understanding of the body” – she is thinking particularly of St John Paul II’s Theology of the Body – points to “a much richer understanding of trans issues than any other philosophy or system of ethics.”

Theology is only just starting to grapple with this. In the meantime, as Mgr Barltrop points out, there is a pastoral need. “In society as a whole, homosexual and trans people are welcomed but in a superficial way which means little,” he argues.

The Church had something better to offer – a real welcome into a community. We should also be providing “spiritual resources”, he says. Gay and trans people should be helped “to form their consciences to lead a life worthy of the Gospel, a life not governed by unbridled passions, but exercising the true inner freedom Christ has won for us on the Cross, and learning how to put their sexuality at the service of a love consistent with the love of God. That of course applies to all Catholics.”

One problem is that words such as “acceptance” and “compassion” are often used to advance pet theories at odds with Catholic teaching. I suggest to the journalist Jane Fae, a trans woman, that even the language of “welcoming” has been corrupted. “I think you’re absolutely right there,” she says, while pointing out that in some places this is a matter of urgency. Since 2008, Brazil has seen 644 murders of trans people; in Mexico, the figure is 177. Both are cultures saturated with Catholicism – and some of the murderers believe they are doing the will of God.

By contrast, Fae remembers being overwhelmed by the “incredible love and acceptance” she received in her own parish. “And at the same time the Church has produced a bunch of homicidal maniacs. I think it’s going to need at some point archbishops, cardinals, hopefully the Pope, to say: ‘No. Whatever else you think about trans people, it’s for the Church to come to a conclusion – and please don’t go around killing them in the meantime.’ ”

Transgender people pose a question to society which has not really been answered. The Church, too, is just beginning to form its answer – but at least we have some idea where to start. “The one thing we know for sure,” says Anna Magdalena, “is that the only way to treat trans people is as being made in the image and likeness of God.”

Dan Hitchens is a freelance writer