I have been focusing, in this article, on the Church’s understanding of Who Jesus is. The idea of Jesus being completely and fully both God and man is a very difficult idea to express. It took years for the Fathers to find the right words and then to understand exactly what those words mean. In Christ, the union of the two natures (i.e., divine and human) is hypostatic: that is they concur into one person and one hypostasis”, according to the Fathers of Chalcedon. (I purposely put in these exact expressions since I believe that it is very important that we Christians understand exactly what the Church calls us to believe about Jesus).

The controversies which naturally arose from the Chalcedonian formula led to further definitions of the meaning of the term hypostasis. While Chalcedon had insisted that Christ was indeed one in His personal identity, it did not clearly specify that the term hypostasis, used to designate this identity, also designated the hypostasis of the pre-existing Logos (i.e., Word – Son of God, the second Person of the Holy Trinity). The anti-Chalcedonian opposition in the East so built its entire argument around this point that Byzantine Christology of the age of Justinian committed itself very strongly to excluding that interpretation of Chalcedon which would have considered the hypostasis, mentioned in the definition, as simply the hypostasis of union” of the old Antiochian School (i.e., the new synthetic reality resulting from the union of the two natures).

I’m not sure whether this is clear. The idea that the Fathers were dealing with is this: since the God-man Jesus is a union of two different natures (i.e., divine and human) in the personhood of Jesus, is the personhood of the combination a new entity because it is a combination or is the personhood still the Divine Personhood of the Son. You can see that this is a very important point since the Fathers believed that there must be a real balance between the divine and     human nature of Jesus, the divine nature not dictating the action of the human nature of Jesus.

The Eastern Fathers affirmed, following Cyril of Alexandria, that Christ’s unique hypostasis is the pre-existing hypostasis of the Logos, meaning that the term is used in Christology with exactly the same meaning as in the Trinitarian theology of the Cappadocian Fathers: one of the three eternal hypostases of the Trinity took flesh, while remaining essentially the same in its divinity. Therefore the hypostasis of Christ, pre-existed in its divinity but it acquired humanity by the Virgin Mary.

Again I would assert that it is important that we Christians understand what we believe when we say that Jesus was both God and man. It is a mystery, obviously, but we should know how to express it.