The defining Christological doctrine of the Ethiopian Orthodox Tewahedo Church is expressed in its very name: 'Tewahedo' means 'being made one' in Ge'ez, referring to the union of divine and human natures in Christ. This is the miaphysite confession: after the Incarnation, Jesus Christ possesses one united nature—fully divine and fully human—joined without mixture, confusion, or separation. The human nature is not absorbed or diminished; rather, the two natures are united in a perfect, inseparable communion.

This Christology, following St. Cyril of Alexandria's teaching, was the theological basis for the Ethiopian church's rejection of the Council of Chalcedon (451). The Ethiopian church does not accept the Chalcedonian two-natures formula, which it has historically read as introducing an unacceptable duality into Christ's person. Modern ecumenical agreements—including the 1989 Agreed Statement between Oriental and Eastern Orthodox churches and various statements with the Catholic Church—have affirmed that the miaphysite and Chalcedonian formulas express the same Christological faith using different terminological frameworks.