LORD’S DAY 6
16. Why must He be a true and righteous man?
Because the justice of God requires1 that the same human nature which has sinned should make satisfaction for sin; but one who is himself a sinner cannot satisfy for others.2
 Rom: 5:15.  Isa. 53:3–5.
17. Why must He also be true God?
That by the power of His Godhead He might bear in His manhood the burden of God’s wrath,1 and so obtain for2 and restore to us righteousness and life.3
 Isa. 53:8; Acts 2:24.  Jn. 3:16; Acts 20:28.  1 Jn. 1:2.
18. But who now is that Mediator, who in one person is true God and also a true and righteous man?
Our Lord Jesus Christ,1 who is freely given unto us for complete redemption and righteousness.2
 Matt. 1:23; 1 Tim. 3:16; Lk. 2:11.  1 Cor. 1:30; *Acts 4:12.
19. From where do you know this?
From the Holy Gospel, which God Himself first revealed in Paradise,1 afterwards proclaimed by the holy patriarchs2 and prophets, and foreshadowed by the sacrifices and other ceremonies of the law,3 and finally fulfilled by His well-beloved Son.4
 Gen. 3:15.  Gen. 22:18; 49:10–11; Rom. 1:2; Heb. 1:1; Acts 3:22–24; 10:43.  Jn. 5:46. Heb. 10:7.  Rom. 10:4; Gal. 4:4–5; *Heb. 10:1.
The Faithful Servant
God created man to be His true and faithful servant, demonstrating and expressing God’s glory in creation by being an image and representation of God. As we saw before, Adam and Eve rejected their role as God’s servants and tried to be independent of Him, and thus fell into ruin along with all their offspring. The Catechism tells us that the One who is to rescue us from that ruined state must be holy Himself, and the reasons are apparent.
If He is not a holy man, then He is under condemnation Himself, and cannot satisfy the wrath of God against anyone else, since His suffering could only ever be applied to His own condemnation, and never satisfy even God’s wrath against Himself. But more than this, the Messiah’s redemption is about a lot more than just getting us off the hook. It is about succeeding where we failed. When Jesus came to earth, He not only paid for our sins, He also perfectly obeyed the law of God. The prophet Isaiah identifies the Messiah as the “Servant of God”, and Jesus emphasizes that He does the deeds His Father does and speaks the words His Father gave Him to speak. This is why the temptations in the desert matter- each of those temptations mirror a failure of Israel in the wilderness, Israel being another archetype of a people that God had blessed and called to be His servants, who failed. So Jesus succeeded in trusting and obeying God where Israel failed and proves Himself to be the faithful servant.
This is hugely important for understanding our salvation. It means that our salvation in Christ is truly complete. He did not just clear the slate so that we could try again with God; He did not die so that earning God’s favor would be easier for us. His entire life and death completely saves us. He fulfills the requirements of the Law in its entirety. He is what Adam was supposed to be. He therefore redeems not only us as individuals; He redeems the very concept of humanity itself, justifying God’s pronouncement over His creation as “very good.”
So question 16 of the Heidelberg tells us the reason why He must be a true and righteous man, expanding on question 14. Only the perfect obedience of a true man can satisfy the demands of God’s law for man, and only a man can pay the penalty for man’s sin. Man’s sin ultimately is not specific acts of wrongdoing, but failing to be what God created man to be. So only by a man succeeding to be what God’s law requires of a man can the righteous requirements of God’s law be fulfilled. Jesus Christ, as revealed in the Scriptures, fulfils the obligation perfectly.
He likewise possesses the power to actually accomplish this herculean task because He is God, and His deity, in a mysterious fashion, upholds His humanity to be able to endure the whole weight of God’s wrath against sin, and to do so in a finite period of time. This is how we can resolve the promise of God to show His people mercy while still exacting the full demand of His justice. He suffers the penalty of His justice Himself and attributes the merits of that perfect obedience and that satisfaction to His people.
So we can have full confidence that Jesus is that Savior. He alone fulfills the promise of God from the beginning, that God Himself would bring salvation to His people, to show them mercy and forgiveness while never abandoning His essential justice. He promised that a man would one day come to Israel, sent by God, the perfect servant of God, to reverse the damage done by Satan to the human race, and bring salvation to Israel and to the whole human race as well. He is the son of David that will sit on the throne forever, the seed of Abraham that would bless the whole human race, the seed of the woman who would crush the serpent’s head. That was the promise developed throughout the Old Testament and finally fulfilled in the New.