Christology: One Christ, Fully Divine and Fully Human
Christology asks who Jesus Christ is and how his divine and human life belong to the one incarnate Son. The Chalcedonian account distinguishes person, the acting subject, from nature, what that subject is. It confesses complete divinity and complete humanity without turning Christ into two persons or blending the two natures into a third kind of being.
Why it matters
The distinctions explain how Christians can attribute both genuinely human experiences and divine action to the same Christ without making his humanity an appearance.
Historical context
Ephesus in 431 defended the identity of Mary's son as the divine Word incarnate. Chalcedon in 451 articulated the distinction of natures within the one Christ. Constantinople III in 680-681 addressed the consequences for his natural willing and activity. These definitions belong to connected debates, not a single meeting or a single author's system.
Key points
- The title Theotokos concerns the identity of the one born of Mary; it does not make Mary the origin of the divine nature.
- Chalcedon's four qualifications exclude both the confusion of divinity and humanity and the division of Christ into two personal subjects.
- The argument that Christ heals what he assumes requires a complete humanity, including a human mind, will, and embodied life.
Scripture
- John 1:1-14 — The Word is with God, is divine, and becomes flesh; the same subject is followed throughout the passage.
- Hebrews 2:14-18 — Sharing flesh and blood and experiencing temptation explain why Christ's real humanity matters for salvation.
- Galatians 4:4-7 — The Son is sent and born of a woman so that human beings may receive adoption.
Primary sources
Chalcedon qualifies its confession of two natures by excluding confusion, change, division, and separation.
in two natures, unconfusedly, immutably, indivisibly, inseparably [united]
Passage context and translation
The definition confesses one and the same Christ in two natures while preserving both their distinction and their union in one person. Oriental Orthodox churches do not receive Chalcedon, even though later dialogues have identified significant shared Christological convictions.
Before the excerpt
This one and the same Jesus Christ, the only-begotten Son [of God] must be confessed to be
After the excerpt
and that without the distinction of natures being taken away by such union
Gregory links the healing of humanity to what the Word actually assumes.
For that which He has not assumed He has not healed; but that which is united to His Godhead is also saved.
Passage context and translation
Gregory rejects Apollinarianism by insisting that the Word assumed the fullness of human nature, including a human mind.
Before the excerpt
If anyone has put his trust in Him as a Man without a human mind, he is really bereft of mind, and quite unworthy of salvation.
After the excerpt
If only half Adam fell, then that which Christ assumes and saves may be half also; but if the whole of his nature fell, it must be united to the whole nature of Him that was begotten, and so be saved as a whole.
Sources and further reading
- Saint Maximus the Confessor and Saint Martin of Rome
Connects complete humanity and Gregory's assumed-and-healed argument with the later debate about will and activity. - Council of Chalcedon
The definition supplies the one-Christ, two-natures formulation and its four qualifications; the catalog's reviewed excerpt is linked above.