What follows is an answer I recently gave to someone asking what the Christian tradition believes concerning the body and gender identity.
The human body is centrally important to the Christian faith. Orthodox Christian theology regards the human person as a psychosomatic (integrated soul-body) unity, according to God’s design in both creation and salvation. The importance of the body can be seen clearly in the Bible, which has binding authority for Christian belief and practice. It is also clearly reflected in Christianity’s major creeds and theological texts. This can be seen in the Apostles’ Creed and the Nicene Creed, which are theological summaries of the Bible’s central teaching, and whose doctrines are accepted by every Christian tradition.
The Creeds reflect the Bible’s affirmation of the original goodness of creation as the good craftsmanship of a good God (Genesis 1). This includes the embodied reality of humanity, made in God’s image as male and female (Genesis 1:26-27). This understanding of humans as sexually dimorphic (as a species, male and female, and as individuals male or female) image-bearers of God is at the heart of historic Christian anthropology.
Following reference to creation, the Creeds then focus attention on the central realities of the Christian gospel: First, Christ’s taking on of human flesh in the incarnation, in which human nature (body and soul) is dignified in its personal union with God’s Son. Then, Christ’s sufferings in human flesh under Pontius Pilate, his death by crucifixion, his burial, and his bodily resurrection from the dead on the third day. Significantly, the Gospels emphasize that Christ’s tomb was empty, and that Christ therefore rose with the same body he had before he died, a body that still bore the marks of the nails with which he was crucified, and the spear with which his side was pierced. Thirdly, both the Bible and the Creeds treat Christ’s resurrection as the certain promise of the bodily resurrection of all people for judgement, and Christian believers for embodied eternal life.
These beliefs lie at the core of the Christian faith. In the words of the Apostles’ Creed: “I believe in God, the Father Almighty, maker of heaven and earth, I believe in Jesus Christ his only Son our Lord, who was conceived by the Holy Spirit, born of the Virgin Mary, suffered under Pontius Pilate, was crucified, died and was buried…on the third day he rose again…I believe in…the forgiveness of sins, the resurrection of the body and the life of the world to come.”
It is a sobering fact for Protestants that on many ethical matters Roman Catholics have done the most sophisticated theological work. One striking example is Pope John Paul II’s work on the theology of the body, a text widely admired by Protestant ethicists. As he identifies, and as I and others have argued more recently, the Bible teaches that the reality of our masculine or feminine gender is not separate from the sexually dimorphic form of our bodies. Rather, our gender is rooted in, flows from, and is discovered in relation to the male or female biological sex of our own body, and in relation to the male or female sex of other human bodies.
This bodily and social reality is not something “assigned” by a midwife, or a parent, at birth. It is, rather, a reality given by God as creator, which can only be recognized as such by his creatures. Christian belief in the resurrection entails that this is not a temporary, or mutable reality. The Apostle Paul teaches in Scripture that the dead will be raised with the body “God has chosen” and assigned in creation (1 Corinthians 15:38). He also teaches that it is this body, the one given in this life, which will be raised clothed in immortal glory (1 Corinthians 15:53-54).
Given Scripture’s authority for orthodox Christian belief and practice, this means that the reality of a person’s bodily form, including their sex and gender at birth, is not malleable. Rather, for orthodox Christian belief, a person’s bodily sex has enduring, God-given, and God-defined ontological significance, regardless of that person’s own feelings or preferences. This teaching—that those created men will be raised as men, and those created women will be raised as women—is confirmed by Augustine in his City of God, which is a foundational Christian text for ethics and political philosophy and theology.
Christian theology and pastoral practice rightly recognizes the agonizing realities of gender dysphoria, and the need for compassion and care for those who experience this distressing condition. However, even as it accounts in sophisticated ways for scientific understandings of sexual development, and developments in philosophy and psychiatry, it cannot recognize that this experience of gender dysphoria is a true reflection of the reality of someone’s sex or gender identity. Rather, it regards a person’s sex and gender identity as defined by their body’s chromosomes and primary and secondary sexual characteristics.
For Christian theology, the meaning of our sex and gender, rooted in and flowering from the biological form of our bodies is not incidental, but intrinsic to our reality as creatures defined not by ourselves, but by God our creator. Christ himself recognized and affirmed the authority of this dimorphic creation pattern of humanity for human life and ethics (Matthew 19:3-12).
However, more than just the pattern of creation as given by God, this male-female unity-in-difference is also fundamental to the central message of the Christian gospel. The Old Testament presents God’s relationship to his people Israel using the metaphor of marriage, with Israel as God’s Bride (e.g., Song of Songs; Jeremiah 2-3; Ezekiel 16; Hosea). Similarly, with the coming of Christ, in the New Testament, Christ is presented as the Church’s husband, and the Church as Christ’s Bride (Ephesians 5:22-33; Revelation 19:6-9). Thus, the bodily reality of humans as male and female, as it finds its natural fulfilment in marriage, is, for the Christian faith, not merely a human reality, but part of a network of signs pointing to the ultimate spiritual meaning of all of reality.
Therefore, for Christians, to reject the meanings of our bodies as they identify our gender is certainly to reject the truth of an individual’s identity. But this rejection also has far greater consequences. It is to reject the truth of who God is, how he creates, saves and relates to his creatures, what it means to be human in God’s world, and, indeed, the central meaning of all created reality and history. It can therefore be seen that how we identify someone’s sex and gender is not a marginal matter, but something of great importance for orthodox Christians. If Christian teaching and practice on this matter is denied or silenced, it would undermine central features of the Christian faith.
Matthew Mason serves as Tutor in Christian Ethics at the Pastors’ Academy of London Seminary. This post first appeared on the Pastors’ Academy blog.
 Eastern Orthodox churches do not use the Apostles’ Creed liturgically, but do not deny anything of the doctrines contained in it, not least because these doctrines are found in slightly expanded form in the Nicene Creed, which is part of their worship.
 See the detailed historical study of Christopher Chenault Roberts, which covers representative theologians from every period of the church’s history from the second century AD to the end of the twentieth century; Creation and Covenant: The Significance of Sexual Difference in the Moral Theology of Marriage (London: T&T Clark, 2007).
 John Paul II. Man and Woman He Created Them: A Theology of the Body. Translated by Michael Waldstein. (Boston: Pauline Books and Media, 2006); Prudence Allen, “Gender Reality vs. Gender Ideology,” Solidarity: The Journal of Catholic Social Thought and Secular Ethics 4, no. 1 (2014): 1–36; Joshua R. Farris, An Introduction to Theological Anthropology: Humans, Both Creaturely and Divine (Grand Rapids: Baker Academic, 2020), 205-230; Margaret McCarthy, “Gender Ideology and the Humanum,” Communio 43, no. 2 (2016): 274–98; Matthew Mason, “The Authority of the Body: Discovering Natural Manhood and Womanhood,” Bulletin of Ecclesial Theology 4, no. 2 (2017): 39–57; idem, “The Wounded It Heals: Gender Dysphoria and the Resurrection of the Body,” in Gerald Hiestand and Todd A. Wilson, eds, Beauty, Order, and Mystery: A Christian Vision of Human Sexuality (Downers Grove, IL: InterVarsity Press, 2017), 87–99.
 See the comments on this text by an eminent contemporary scholar, Revd Professor Anthony Thiselton; The First Epistle to the Corinthians (Grand Rapids: Eerdmans, 2000), 1264.
 That is, it defines the reality of who and what someone is.
 Augustine, City of God, xxii.17.
 See, e.g., the work of Dr. Mark Yarhouse, a Christian Professor of Psychology, and Dr Julia Sadusky, a Christian licensed as a psychologist; Mark Yarhouse, Understanding Gender Dysphoria: Navigating Transgender Issues in a Changing Culture (Downers Grove: IVP Academic, 2015); Mark Yarhouse and Julia Sadusky, “The Complexities of Gender Identity: Toward a More Nuanced Response to the Transgender Experience,” in James K. Beilby and Paul Rhodes Eddy, eds, Understanding Transgender Identities: Four Views (Grand Rapids, MI: Baker Academic, 2019), 101-30.
 E.g., Ryan Anderson, When Harry Became Sally: Responding to the Transgender Moment (New York: Encounter Books, 2018), 77-92.
 E.g., Carl Trueman, The Rise and Triumph of the Modern Self (Wheaton: Crossway, 2020); Yarhouse, Understanding Gender Dysphoria; Yarhouse and Sadusky, “Complexities.”
 See, e.g., the analysis by the preeminent living Christian ethicist, Revd Professor Oliver O’Donovan, in a work written while he was Regius Professor of Moral and Pastoral Theology at the University of Oxford; Transsexualism: Issues and Argument (Cambridge: Grove Books, 2007); also Anderson, When Harry Became Sally.