"14 Since therefore the children share in flesh and blood, he himself likewise partook of the same things, that through death he might destroy the one who has the power of death, that is, the devil, 15 and deliver all those who through fear of death were subject to lifelong slavery. 16 For surely it is not angels that he helps, but he helps the offspring of Abraham. 17 Therefore he had to be made like his brothers in every respect, so that he might become a merciful and faithful high priest in the service of God, to make propitiation for the sins of the people. 18 For because he himself has suffered when tempted, he is able to help those who are being tempted."
Hebrews 2:14-18
The third statement about the death of Christ is found in 17. Here Christ is spoken of as making reconciliation for the sins of His people. The word in the Greek is the word translated elsewhere in the New Testament as propitiation. This is a word which speaks of the controversy that sin has raised between man and God and of the turning away of the divine anger by the atoning blood of our great Mediator. We are thus brought to the very heart of the idea of substitution. For this is the predicament, that while atonement, to be real and effectual, must come from man, man because of his sin cannot make that atonement. Not only so. The problem is so great, so infinite, that only a God could deal with it. And into this mystery our Lord entered, very God and very man, the God-man Mediator, and as God and man met the infinite responsibilities of the situation in the death that He died. Newman's wonderful hymn, 'Praise to the holiest' (C.H. 32) expresses this as surely and precisely as any outside Holy Writ in the double paradox of the words: O generous love; that He Who smote In man, for man, the foe, The double agony in man For man should undergo. In man - for man, yea, God as man grappling with the mystery of iniquity and once for all making full atonement. What could not such a Saviour do for us!