“The Son of Man came not to be served but to serve, and to give his life as a ransom for man.” -Mark 10:45
Reflecting on this verse in light of Christmas, John Piper wrote:
Paul put it like this in Galatians 4:4-5: “When the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons.” In other words, the redemption, or the ransom, frees us to be a part of God’s family. We had run away and sold ourselves into slavery. But God pays a ransom and redeems us out of slavery into the Father’s house.
To do that, God’s Son had to become human so that he could suffer and die in our place to pay the ransom. That is the meaning of Christmas. Hebrews 2:14 puts it like this: “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.”
In other words, the reason Christ took on our full humanity was that he could die and in dying pay a ransom and free us from the power of death. And free us to be included in his own family. The ransom is ultimately about relationship. Yours to God, your merciful Father. (The Dawning of Indestructible Joy, pgs. 53-54, emphasis mine)