Throughout the Eranistes, which arguably is the expression of the mature Christological thought of Theodoret of Cyrrhus, it is argued that the divine nature remains immutable and unchangeable. However, the human nature of Christ is said to have acquired extraordinary properties not proper to a human nature. Theodoret explicitly affirms that, despite this change, in the incarnation the human nature of Christ was not changed into the nature of the Godhead.
In my paper I argue that Christ’s resurrection is the turning point in the existence of the person of Christ, the moment which marks the beginning of the exchange of attributes (communication idiomatum). The reason for this chronological marker is simple: Theodoret’s concept of Incarnation is defined by its purpose — the salvation of the human race. The sole purpose of the Logos’s Incarnation is the repayment of the debt of the Protoplast and the human race which followed in his fall. The sacrifice of an equally perfect human being was required to restore the fallen human race. Thus, it was necessary that Christ be a complete and perfect human being in order to accomplish that mission. Once the mission was completed by the death on the cross and the resurrection, it was no longer necessary for the human nature to retain all of its attributes, and the time had come for it to receive its due glory: it began sharing in the attributes of the divine nature.