[This article was taken from our book “Don’t Blame God! A Biblical Answer to the Problem of Evil, Sin, and Suffering.”]
Two primary qualities of God help us understand why Jesus Christ had to suffer and die in order to redeem mankind. First, God is righteous. Thus His justice demands that a penalty for sin be paid. As Kenyon writes:
God cannot ignore the fact of man’s hideous transgression. That transgression must be punished, and if man is restored to God, it must be upon grounds that will not pauperize man nor rob him of his self respect; but it must be upon legal grounds that will perfectly justify man in the sight of God… 
Second, God is love. Thus, in His grace and mercy, He decreed that the penalty for sin could be paid by a substitute, providing that the substitute be sinless. God wanted, and mankind needed, a man who:
…met the demands, first, of the heart of Deity for a perfect human who would do His will; second, He met the demands of fallen man in that as a man He met the Devil and conquered him in honorable open combat. 
Because of the magnitude of Adam’s sin and its reverberating ramifications, only the death penalty would satisfy true justice. Hebrews 9:22 says that “without the shedding of blood there is no forgiveness [of sin].” In the Old Testament, it was the death of unblemished “stand-in” lambs and other animals that God allowed to temporarily cover His people’s sins (Heb. 10:1-14). These sacrifices were foreshadows, or types, of the coming Redeemer, Jesus Christ. He is the true “Lamb of God” whose blood was shed to take away the sin of the world (John 1:29).
How much more, then, will the blood of Christ, who through the eternal Spirit offered himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!
As we have stated, Jesus Christ was the only man who was “without spot or blemish,” both genetically and behaviorally. As such, only he could qualify to offer his life as the payment for the sin and sins of mankind. The suffering and death of Jesus Christ was part of God’s plan to make available salvation to all mankind.
Hebrews 9:27 and 28
(27) Just as man is destined to die once, and after that to face judgment,
(28) So Christ was sacrificed once to take away the sins of many people; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.
What the blood of bulls and goats could do only temporarily for Israel in the Old Testament, the blood of Jesus has done once and for all for everyone who believes in him. He bore our sins in his own body on the cross (1 Pet. 2:24). By his freedom of will he gave up his life for us. He willingly endured the pain of the cross and death for all men. We must understand, however, that it was not God who was responsible for Jesus’ death. Note the following verses:
1 Corinthians 2:7 and 8
(7) No, we speak of God’s secret wisdom, a wisdom that has been hidden and that God destined for our glory before time began.
(8) None of the rulers of this age understood it, for if they had, they would not have crucified the Lord of glory.
The “rulers of this age” are Satan and his evil-spirit sidekicks (the disobedient angels that were cast down to earth with him). God’s Word plainly says that it is the Devil who was responsible for killing Jesus Christ.
Once the dominion of the world was given to Satan, and mankind was ruined by sin, God has had to ask people to step into harm’s way so that His redemptive purposes could be accomplished. Jesus Christ is the chief example of this, and there are many others (see Hebrews 11). Jesus suffered so that those who believe on him can one day have peace and joy forever, and a taste of it even in this life. In Jesus, we see the epitome of the redemptive value of suffering, a subject we will discuss later.
Hebrews 5:7-9 (Moffatt)
In the days of his flesh, with bitter cries and tears, he offered prayers and supplications to Him who was able to save him from death; and he was heard, because of his godly fear. Thus, Son though he was, he learned by all he suffered how to obey, and by being THUS PERFECTED he became the source of eternal salvation for all who obey him, being designated by God high priest with the rank of Melchizedek.
We feel the Moffatt translation (e.g.,“thus perfected”) best represents the truth of the Greek text that Jesus attained moral perfection through suffering and death. It was God who totally “perfected” Jesus by raising Him from the dead with a glorious new body and exalting Him as Lord, as the following verses make clear:
(9) But we see Jesus, who was made a little lower than the angels, now crowned with glory and honor because he suffered death, so that by the grace of God he might taste death for everyone.
(10) In bringing many sons to glory, it was fitting that God, for whom and through whom everything exists, should make the author of their salvation perfect through suffering.
(11) Both the one who makes men holy and those who are made holy are of the same family. So Jesus is not ashamed to call them brothers.
Jesus Christ is the Last Adam, the fulfillment of God’s prophecy in Genesis 3:15. As our Redeemer, Jesus purchased our salvation with his own blood. He provided, and is, the way back to God that Adam had lost. Those who confess him as Lord and believe in his resurrection are saved, fully equipped to live in this corrupted world and guaranteed ultimate and everlasting victory over sin and death, as we shall see. [For further study read How can a man atone for the sins of mankind?]
 Kenyon, The Father and His Family, page 115.
 Ibid., page 192.