Jesus Christ. Son of God. Son of Man.
The Bible tells us that He is both these things and simply by the exalted nature of them, these statements carry a lot of weight. I want to understand them, and understand well.
The idea that Jesus is the Son of God seems the easier of the two. After all, the Father Himself declares a number of times that Jesus is His Beloved Son. And I know what a son is. I have two of them. So, if God the Father has a Son, their relationship and shared common nature make sense.
Son of Man, not so much. If Christ is the Son of God, how could He be the son of men as well? And why? And yet, in the Bible, He declares that He is. Son of Man is Jesus' name for Himself.
What do men say that I, Son of Man, am?--Matthew 16:13
Well, it turns out that I'm not the only one who wanted to understand this better. Iraneus, the bishop of Lyons from 177-200 AD, had quite a bit to say about it.*
First, he observed, Jesus passed through every stage of human life. As Adam was made from untilled virgin earth never knowing rain, so did Christ begin His human life in the womb of a virgin. That was the beginning. Afterwards, He grew through common years like any man--preborn, infant, juvenile, adult, and even corpse--so that no man can say he has been left behind in his peculiar state. Christ became fellow of us all. He did not live outside human frailty at any time in his earthly life. Instead, He sanctified all stages and states of life by sharing them.
Christ, as Son of Man, was like me, no matter who I am.
Second, by the very act of taking on flesh, by participating in incarnation, Christ reunited man to God. The fact of His humanity made Him mediator between God and Man.
I think that this is kind of like forgiveness--it happens in stages. The first stage is that in which we forgive an unrepentant sinner to free our own spirit from bitterness and hatred, but in which the complete relationship is not yet restored. So did God come down to unrepentant, clueless man and present Himself, ready and waiting. The second stage, in which our relationship with the sinner is restored through repentance, Christ lived out in His own suffering and death. That freed all penitents to walk through the now-torn veil directly back to the Father.
Christ, as Son of Man, led the way for all men.
Third, Christ overcame Satan as only a man could have done. From the very beginning of His ministry, He exposed Satan's rebellion when He said,
It is written: Worship the Lord thy God and Him only shall you serve.--Luke 4:8
So man, through the Son of Man, nullifies the power of Satan that Adam admitted in Eden. By His own obedience and submission, Christ put Satan in his place.
Later, He goes even further by subjecting Himself to disgrace and physical suffering. Had He not done so, God would have asked men to endure the scourge and turning the other cheek, something He Himself had not endured, effectively elevating the servant above the master. This, He could not do.
And then, when He became the first man to die and rise again, He showed Himself to be the Author of Life, who goes before us all to show the way.
Christ as Son of Man shows me what He created man to be.
In the end, if Christ is not Son of Man, I have no way to understand either the nature of God nor the nature of Man. Only through Him can I understand what I am created to become. Only through His humanity do I understand my own.
*Iraneus, Against Heresies, III