Is God the Son's divine nature human? According to the hypostatic union, God the Son assumed a human nature, so that he is both fully divine and fully human. The two natures, although distinct, are not separated.

Does this mean god the son's divine nature is fully human?

If not, what does "without division, without separation" mean?
No, according to the doctrine of the Hypostatic Union, the divine nature did not become fully human, or even partially human.

From the Formula of Chalcedon:


  one and the same Christ, Son, Lord, Only-begotten, recognized in two natures, without confusion, without change, without division, without separation; the distinction of natures being in no way annulled by the union, but rather the characteristics of each nature being preserved and coming together to form one person and subsistence


The divine nature is united with the human nature in person of Jesus Christ, but it is unchanged by this union.

Much of the confusion around the HU is placing the two natures in the same category with the person. The person is fully human and fully divine, but the two natures are unchanged.

You ask


  What does "without division, without separation" mean?


It means that the two natures can not be separated from each other when discussing the person Jesus. We can not divide the properties of Jesus between the two natures. We all agree that the person Jesus was born of Mary. Under the HU, we can not separate the two natures and say that the man (only) Jesus was born of Mary. We must always say as well that God was born of Mary.

The two natures are united in the person of Jesus but are not changed by the union. The union is so ' stong' that we can not find any separation or division in Jesus.