Gender, Biological Sex & Trans People
Before we can ask what Jesus would say about gender identity, we need to be honest about something biology has been telling us for decades: biological sex is not a binary. The human body is more complex than two check-boxes — and the tradition has the tools to engage that complexity with more honesty than most culture-war arguments allow.
The Answer
The cultural debate about transgender people is often framed as a conflict between "biological reality" and "gender ideology" — with one side claiming that science settles the question in favor of a strict male/female binary, and the other side claiming that gender is entirely socially constructed.
Both framings are too simple. And the tradition that Jesus came from has always been suspicious of oversimplified answers to complicated human realities.
Let's start with the biology — not the politics, the biology.
Human chromosomal variation is more complex than the XY/XX model most of us learned in school. In addition to the typical XX (female) and XY (male), there are documented chromosomal patterns including:
- XXY (Klinefelter syndrome) — approximately 1 in 500–1,000 male births. People with XXY chromosomes typically appear male but may have a range of physical characteristics that don't fit the standard male template.
- XYY — approximately 1 in 1,000 male births. Usually physically typical males, sometimes taller than average.
- XXX (Trisomy X) — approximately 1 in 1,000 female births. Usually physically typical females; often goes undiagnosed. People with three X chromosomes are biologically real and relatively common.
- X0 (Turner syndrome) — one X chromosome, no second sex chromosome. Approximately 1 in 2,500 female births.
- Various mosaic patterns — where some cells have one chromosomal pattern and others have another.
Beyond chromosomes, sex is also determined by hormone levels during fetal development, hormone receptor sensitivity, gonadal anatomy, and secondary sex characteristics — none of which are always perfectly correlated with each other or with chromosomal pattern. Intersex conditions — where a person's anatomy, chromosomes, or hormones don't fit standard male or female definitions — occur in approximately 1.7% of the population, roughly the same frequency as red hair.
The strict biological binary is not what biology actually teaches. It is a simplification of biology, useful for most cases and wrong for a significant number of real human beings.
With that foundation established: what does the tradition say about people whose bodies, identities, or experiences don't fit the standard categories?
Jesus himself addressed this directly — more directly than most people realize. In Matthew 19:12, discussing marriage, Jesus says: "There are eunuchs who were born that way, and there are eunuchs who have been made eunuchs by others, and there are eunuchs who have chosen to become eunuchs for the sake of the kingdom of heaven." He is describing, in the language of his time, people whose bodies or identities placed them outside the standard male/female social categories — people born that way, people altered by others, and people who chose a different path. He does not condemn any of them. He acknowledges their existence as part of the human landscape.
The Jewish Reformer's Lens
The Talmud recognizes not two but six gender categories, developed through centuries of careful observation of human variation. These are not modern inventions projected backward — they are ancient rabbinic legal categories developed specifically because the rabbis encountered people who didn't fit the binary and needed a legal framework to address their situations:
- Zachar — male
- Nekevah — female
- Androgynos — a person with both male and female characteristics (discussed in 32 places in the Mishnah, 83 places in the Talmud)
- Tumtum — a person whose sex characteristics are indeterminate or hidden
- Ay'lonit — a person who appears female at birth but develops in ways that diverge from typical female development
- Saris — a person who appears male at birth but develops in ways that diverge from typical male development (including naturally and through human intervention)
The sheer detail with which the rabbis discussed these categories — how they apply to property law, marriage law, ritual obligations, testimony — reflects a tradition that took human complexity seriously rather than forcing it into two boxes. These are not contemporary categories read back into ancient texts. They are ancient categories, developed precisely because real people existed who didn't fit the standard template.
The concept of kvod habriot (human dignity) applies universally in Jewish law. The Talmud (Berakhot 19b) states that human dignity is of such importance that it can override rabbinic prohibitions. Whatever the specific legal debates about any particular situation, the dignity of the person in front of you is never in question.
The contemporary Reform and Conservative Jewish movements have both affirmed the full inclusion of transgender people in Jewish communal life, the validity of gender transition, and the use of preferred names and pronouns. These decisions were made after extensive study of the tradition — including the six gender categories above — and represent a direct application of the tradition's own categories to contemporary questions.
Catholic Social Teaching
The Catholic Church's official teaching on gender identity is in significant tension — tension the Church itself acknowledges. The official doctrinal documents (Fiducia Supplicans, 2023; the Dicastery for the Doctrine of the Faith's Infinite Dignity, 2024) affirm the absolute dignity of every transgender person while opposing gender-affirming medical interventions as incompatible with the Church's understanding of the body as a gift with a given nature.
This is a genuine disagreement with real theological stakes, not a simple political dispute. The Church's position is grounded in a theology of the body developed extensively by John Paul II — the idea that the body has inherent meaning that cannot be voluntarily negated.
However, several things are simultaneously true and worth holding alongside the Church's official position:
The Church condemns discrimination and violence. Infinite Dignity explicitly states: "The dignity of every human person is to be respected and protected regardless of gender identity." Bullying, exclusion, violence, and legal discrimination against transgender people are condemned by the same document that questions gender-affirming care.
The science of intersex conditions complicates the "clear biological binary" claim. The existence of people with chromosomal variations (XXX, XXY, X0, etc.), intersex anatomy, and hormonal conditions that produce bodies that don't fit the binary is not a modern ideology. It is medical fact documented across the entire span of human history. The tradition's claim that God makes human beings with bodies that have "given meaning" cannot dodge the question of what that meaning is for a person born with ambiguous or variable biology.
Pastoral practice and doctrine are not identical. Many Catholic theologians, pastoral workers, and bishops in many countries have arrived at more open pastoral approaches than the official doctrinal position — recognizing that the suffering of trans people is real, that suicide rates among trans youth are alarmingly high, and that pastoral accompaniment cannot look like condemnation.
The question of children is distinct. The Church's concern about irreversible medical interventions on minors is shared by some secular medical bodies and some trans advocates. This is a genuine area of medical debate, not only a religious position. That debate deserves more nuance than the culture war tends to allow it.
Sources & Citations
- Matthew 19:12 — Eunuchs from Birth (New Testament) One of the four Gospels. In a discussion of marriage and divorce, Jesus references three categories of eunuchs: those born that way, those made eunuchs by others, and those who chose it for religious reasons. In his cultural context, "eunuch" encompassed a broader range of people who existed outside standard male/female social roles — including people we might now describe as intersex or gender-variant. Jesus acknowledges their existence without condemnation and treats the category as self-evidently part of human reality.
- Isaiah 56:3–5 — Eunuchs in God's House (Hebrew Bible) One of the Major Prophets. God promises to the eunuch who keeps the Sabbath and holds fast to the covenant: "I will give them an everlasting name that will endure forever." Deuteronomy 23:1 excluded eunuchs from the assembly. This passage in Isaiah explicitly reverses that exclusion — God promises eunuchs a place and a name in the divine household. Early Christian interpreters, including Ethiopian treasurer of Acts 8, understood this as a deliberate extension of inclusion to those previously excluded by their bodies.
- Mishnah, Bikkurim 4:1–5 — The Androgynos (Talmud) A tractate of the Mishnah. The entire fourth chapter addresses the legal status of the *androgynos* (a person with both male and female characteristics), carefully distinguishing which legal obligations apply. The text notes: "In some ways the androgynos is like men, and in some ways like women, and in some ways like both men and women, and in some ways like neither." This is not a dismissal of the category — it is a careful, serious legal engagement with human complexity that resists forcing people into boxes they don't fit.
- Leonard Sax, "How Common is Intersex?" (Journal of Sex Research, 2002) A peer-reviewed medical study examining the prevalence of intersex conditions. Using a careful definition of intersex (conditions where chromosomal sex is inconsistent with phenotypic sex, or where phenotype is not classifiable as typically male or female), finds a prevalence of approximately 0.018%. Broader definitions, including chromosomal variations like Klinefelter (XXY) and Trisomy X (XXX), yield prevalence estimates approaching 1.7%. The study is cited both by those who consider intersex common and by those who consider it rare, depending on which definition is used.
- Dicastery for the Doctrine of the Faith, Infinite Dignity (2024) The Vatican's most recent major document on human dignity. Addresses gender identity directly, opposing gender-affirming medical interventions while simultaneously condemning discrimination, violence, and marginalization of transgender people. Represents the current official Catholic position — a position that contains real internal tension between doctrinal anthropology and pastoral concern that the document acknowledges without resolving.
- Acts 8:26–40 — The Ethiopian Eunuch (New Testament) The Book of Acts (history of the early Church). Philip encounters an Ethiopian eunuch — an official of the Ethiopian queen — reading Isaiah 56 in his chariot. Philip explains the passage, the eunuch asks to be baptized, and Philip baptizes him without condition or delay. The eunuch is the first recorded Gentile convert in Acts. The story is read by many theologians as a deliberate fulfillment of Isaiah 56's promise: the person whose body excluded them from the assembly becomes the first to carry the Gospel to Africa.
What Should We Do?
For everyone: Start with the biology. The insistence that sex is a strict binary, with no exceptions or variation, is not what biology teaches. Chromosomal variations including XXX (Trisomy X), XXY (Klinefelter syndrome), X0 (Turner syndrome), and XYY affect roughly 1 in 500 people in various forms. Intersex conditions affecting anatomy and hormones are similarly common. Before having an opinion about "what the Bible says about gender," be honest about what the human body actually is. Real people are sitting in your church, your classroom, and your family with chromosomal and anatomical variations that the culture-war binary cannot account for. Their existence is not a political statement. It is a medical fact.
The Talmud's six gender categories were developed not by progressive activists but by ancient rabbis who simply paid careful attention to the human beings in front of them. That is a model worth following: look at the actual person, not the category you need them to fit into.
For the trans people in your life: the data on mental health outcomes is clear. Trans people who have family acceptance and community support have dramatically better mental health outcomes — including dramatically lower suicide rates — than those who face rejection. Whatever your theological position on gender-affirming medical interventions, your posture toward the trans person in front of you has measurable life-or-death consequences. The tradition of Jesus, which consistently chose the person over the category, points in one direction: accompaniment, presence, dignity.
For Catholics specifically: The Church teaches simultaneously that trans people deserve full human dignity and that gender-affirming medical interventions are problematic. You can hold the second position while being absolute about the first. The condemnation of discrimination, bullying, family rejection, and violence against trans people in Infinite Dignity is not a footnote to the doctrinal position. It is equally official teaching. If your parish community treats trans people as unwelcome, it is violating official Church teaching just as surely as if it endorsed something the Church forbids. The door is open. That is not a liberal gloss on the tradition. It is what the document actually says.