Theotokos: Why Mary is Truly the Mother of God

The Historical Defense of “Theotokos” and the Person of Christ

The Christological Question at the Heart of the Controversy

Why do we call Mary the “Mother of God” or “God-bearer” (Theotokos)? The historical controversy surrounding the identity of Mary revolves around the identity of Jesus Christ. Who and what did the Virgin bear in her womb? 

Christological questions gave rise to new philosophical and theological concepts such as hypostasis (person) and prosopon (face or person). Speculations also arose concerning the two natures of Christ—his physis (nature) and ousia (essence). Some Church Fathers emphasized the unity of Christ’s single hypostasis (person), while others focused on distinguishing the two natures to prevent any mixing of his divinity with his humanity.

Nestorius and the Rejection of “Theotokos”

Did Mary bear the very Son of God, eternally begotten of the Father, the Logos who assumed human nature as one hypostasis or person? Or did she bear only the man, Jesus Christ, separated from his divine nature, as the monk Nestorius, Patriarch of Constantinople, proposed? Arguing that Mary, as a human, could not bear God, who was impassible (incapable of suffering or change) and eternal, Nestorius rejected the title of “Theotokos.” Instead, he proposed “Christotokos” (Christ-bearer) or even “Anthropotokos” (man-bearer), insisting Mary gave birth only to Christ’s human nature, which was conjoined to the divine by will or dignity, not in a full hypostatic union.

The Patristic Resolution: One Person, Two Natures

How did the Fathers resolve the dispute? The key to Christ’s identity hinged on understanding his relationship of eternal sonship in the Father. Just as the Father does not beget the divine nature or essence alone but the Son, Mary does not beget the human nature alone but the Son himself. “Man” (humanity) and “God” (divinity) do not denote the person (“who”) but the nature or essence (“what”). Thus, to the question “Who is Jesus Christ?” we answer, “The Son of God.” To the question “What is he?” we answer, “God and man.”

In the Christian theology of the Incarnation, Christ’s human nature is said to be “enhypostasized” in the divine hypostasis of the Son (the second person of the Trinity). This means Christ’s human nature does not have its own independent hypostasis or person but exists concretely as part of the Son’s single, divine person. The human nature is real and complete but is “held” within the Son’s hypostasis, ensuring Christ is one person with two natures (divine and human), not two separate persons. Because of the ambiguity of terminology at the time, Nestorius appeared to propose two persons (divine and human) in Christ, supposing that each nature required its own hypostasis.

Perichoresis: The Interpenetration of Christ’s Two Natures

How, then, do Christ’s two natures remain intact—without mixture, confusion, or dilution—that is, without producing a third, hybrid reality that is neither fully divine nor fully human? St. Maximus the Confessor applied the concept of perichoresis (“dance”), describing the interpenetration of the three divine persons, to the two natures of Christ. Just as the Father, Son, and Holy Spirit wholly exist in one another in perfect union and distinction, so the two natures of Christ also interpenetrate one another in the hypostasis of the Son. The poem below offers the expression “whole in whole” to describe this perichoretic union and distinction:

Two natures, whole in whole, in one
Person of Christ, the Father’s Son.

The primacy of Christ’s hypostatic union prevailed in the end; the Council of Ephesus in 431 AD definitively declared Mary Theotokos (“God-bearer” or “Mother of God”). Thus, Mary truly leads us to the Father through his Son, Jesus Christ, who is fully God and fully man. 

Hymn to the Theotokos: Bearer of the Eternal Son

We call Mary Theotokos,
The Mother of God—the Logos,
Abba’s only-begotten Son
In eternal generation.

The whole Christ, in her womb, she bore—
God and man, whom angels adore.
Indivisibly one, the Lamb
Sent to be slain declares, “I AM.”

How can heaven and earth unite?
Can finite flesh be one with Light?
The Son assumed humanity
In wholeness with divinity:

Two natures, whole in whole, in one
Person of Christ, the Father’s Son.
The Theotokos bore our Lord,
That our cosmos may be restored.