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, and deliver all those who through fear of death were subject to lifelong slavery. ( Hebrews 2:14 14 Since then the children are sharers in flesh and blood, he also himself in like manner partook of the same; that through death he might bring to nought him that had the power of death, that is, the devil; –15)

These verses connect the beginning and the end of Jesus’ earthly life. They make clear why he came.

Since then the children share in flesh and blood . . .

The term “children” is taken from the previous verse and refers to the spiritual offspring of Christ, the Messiah. (cf. Isaiah 8:18 18 Behold, I and the children whom Jehovah hath given me are for signs and for wonders in Israel from Jehovah of hosts, who dwelleth in mount Zion. ; 53:10). These are also the “children of God.” In other words, in sending Christ, God has the salvation of his “children” especially in view. It is true that “God so loved the world, that he sent [Jesus].” But it is also true that God was especially “gathering the children of God who are scattered abroad” ( John 11:52 52 and not for the nation only, but that he might also gather together into one the children of God that are scattered abroad. ).

He Himself likewise also partook of the same [flesh and blood] . . .

Christ existed before the incarnation. He was spirit. He was the eternal Word. He was with God and was God ( John 1:1 Chapter 1 1 In the beginning was the Word, and the Word was with God, and the Word was God. ; Colossians 2:9 9 for in him dwelleth all the fulness of the Godhead bodily, ). But he took on flesh and blood and clothed his deity with humanity. He became fully man and remained fully God.

that through death . . .

The reason he became man was to die. As God, he could not die for sinners. But as man he could. His aim was to die. Good Friday is the reason for Christmas.

He might render powerless him who had the power of death, that is, the devil . . .

In dying Christ de-fanged the devil. How? By covering all our sin. This means that Satan has no legitimate grounds to accuse us before God. “Who shall bring any charge against God’s elect, it is God who justifies” ( Romans 8:33 33 Who shall lay anything to the charge of God's elect? It is God that justifieth; ) — on what grounds does he justify? Through the blood of Jesus ( Romans 5:9 9 Much more then, being now justified by his blood, shall we be saved from the wrath `of God' through him. ). Satan’s ultimate weapon against us is our own sin. If the death of Jesus takes it away, the chief weapon of the devil is taken out of his hand.

and might deliver those who through fear of death were subject to slavery all their lives.

So we are free from the fear of death. God has justified us. Satan cannot overturn that decree. And God means for our ultimate safety to have an immediate effect on our lives. He means for the happy ending to take away the slavery and fear of the Now. If we do not need to fear our last and greatest enemy, death, then we do not need to fear anything.