Jesus didn't become less God when He became human—He became fully human while remaining fully God. Dyophysitism protects this essential truth, showing that only the God-man could both represent us in death and save us from our sins.
Dyophysitism is a historical argument about the dual natures of Christ. Dyo means “two” and physis means “nature.” It is the orthodox position in contrast to Monophysitism, which argued that Christ had only one nature. The importance lies in what it means that Jesus was born human. Jesus had to be like us in every way (Hebrews 2:17), meaning He needed a true nature. If Jesus were not true human, as Monophysitism argued, then He would not have been able to die as a substitute for our sins (Hebrews 2:14). Additionally, if Jesus’ natures were mixed or absorbed into a single nature, then He would have ceased to be the Son of God, as His divine nature would have changed. Yet Jesus continued to affirm His full divinity despite being human (e.g., John 10:30). Nestorianism, another position, overcorrected the Monophysitism position by dividing Jesus into two distinct Persons. However, Dyophysitism’s position, rightly understood, is that Jesus’ natures relate in what is called the hypostatic union, meaning that Jesus’ natures are neither mixed nor separated. While a deeply theological discussion, believers today benefit from the careful and precise definitions of the early church. Their work is our heritage, and as we carefully handle God's Word, we will also pass along the truth to the next generation.
The Dyophysitism position was a theological argument in the fifth century that held that Jesus had two true natures, in contrast to Monophysitism, which held that He had only one divine nature, with His human nature absorbed into it. A subsequent error, Nestorianism, overcorrected Monophysitism by effectively saying that Jesus was two separate Persons. However, the orthodox position is Dyophysitism, teaching that Jesus had two natures that were neither mixed nor so fully separated as to create separate Persons. That “not mixed but not separated” position is known theologically as the hypostatic union of Christ.
Dyophysitism is
like many theological arguments in that, to the modern reader, they sound obtuse,
even unnecessary. However, they exist because the early church wrestled with
Scripture as it fought against heretics who attacked core Scriptural truths
about Jesus. Indeed, much of what you take for granted today as obvious is only
so because people spent a lot of time searching the Scriptures to protect
the truth from error. Thus, while theological topics such as Dyophysitism sound
abstract, they are, in fact, attempts to define Jesus precisely in ways that both
conform to what Scripture reveals and acknowledge the limits of the human mind in comprehending everything.
And the dual
nature of Christ is not a minor or abstract theological discussion. It speaks
to whether or not Jesus can save us. The reason that the blood of bulls and
goats could not save us (Hebrews 10:4) was that they were not equivalent to
us. This is why Jesus came—to be a sacrifice that was exactly like us, but
without sin (Hebrews 4:15).
However, being
like us doesn’t mean He stopped being God. If He stopped being God, then
doctrines such as the immutability (unchanging nature) of God would be in doubt
(Malachi 3:6) and Jesus’ ability to be a true bridge between humans and God
would also be at risk (1 Timothy 2:5). Finally, if He were not fully God, then
Scripture (John 1:1) and Jesus (John 10:30) lied when they said He was!
Believer—appreciate
your heritage. Not everything in church history was perfect, but don’t shun it
either. Your brothers and sisters fought hard to protect the truth so that you
can truly know Jesus and the Father today. Praise God for how He worked through
those individuals and pass along the truth you have received to the next
generation (2 Timothy 2:2)!