What Unique religious belief of Coptic Christians included what?

Coptic Christians, who primarily belong to the Coptic Orthodox Church, hold a unique belief in the nature of Christ, specifically the doctrine of Miaphysitism. This doctrine asserts that in the one divine person of Christ, His divine and human natures are united in a single nature "without confusion, without change, without division, and without separation." This belief distinguishes them from other Christian denominations that adhere to the Chalcedonian definition of two natures in Christ. Additionally, Coptic Christianity emphasizes the significance of the sacraments, monasticism, and the veneration of saints and martyrs.