Nature of Jesus

The defining Christological doctrine of the Oriental Orthodox churches is miaphysitism: after the Incarnation, Jesus Christ possesses one united nature—fully divine and fully human—inseparably joined without mixture, confusion, or separation. This formula uses the Greek prefix 'mia' (one in a unified sense) rather than 'mono' (one alone), deliberately rejecting the Monophysite heresy that the human nature was absorbed or diminished. Oriental Orthodox churches strongly distinguish their teaching from Monophysitism, which they, like Chalcedonians, reject.

This Christology is rooted in the theology of St. Cyril of Alexandria, who used the phrase 'one nature (physis) of the Word of God incarnate.' The Council of Chalcedon (451) and its two-natures formula ('two natures without confusion, change, division, or separation') was rejected by Oriental Orthodox churches as introducing a problematic Nestorian-leaning duality. Modern ecumenical dialogues—particularly the Common Declarations with Rome and the Eastern Orthodox—have established that both traditions confess the same faith regarding Christ's person, using different terminological frameworks. These agreements acknowledge that the Chalcedonian and miaphysite formulas are complementary rather than contradictory.