Luk 1:27 to a virgin betrothed to a man whose name was Joseph, of the house of David. And the virgin's name was Mary.
Luk 1:28 And he came to her and said, "Greetings, O favored one, the Lord is with you!"
Luk 1:29 But she was greatly troubled at the saying, and tried to discern what sort of greeting this might be.
Luk 1:30 And the angel said to her, "Do not be afraid, Mary, for you have found favor with God.
Luk 1:31 And behold, you will conceive in your womb and bear a son, and you shall call his name Jesus.
Luk 1:32 He will be great and will be called the Son of the Most High. And the Lord God will give to him the throne of his father David,
Luk 1:33 and he will reign over the house of Jacob forever, and of his kingdom there will be no end."
Isa 9:7 Of the increase of his government and of peace there will be no end, on the throne of David and over his kingdom, to establish it and to uphold it with justice and with righteousness from this time forth and forevermore. The zeal of the LORD of hosts will do this.
Heb 10:4 For it is impossible for the blood of bulls and goats to take away sins.
Heb 10:5 Consequently, when Christ came into the world, he said, "Sacrifices and offerings you have not desired, but a body have you prepared for me;
Heb 10:6 in burnt offerings and sin offerings you have taken no pleasure.
Heb 10:7 Then I said, 'Behold, I have come to do your will, O God, as it is written of me in the scroll of the book.'"
Heb 10:8 When he said above, "You have neither desired nor taken pleasure in sacrifices and offerings and burnt offerings and sin offerings" (these are offered according to the law),
Heb 10:9 then he added, "Behold, I have come to do your will." He does away with the first in order to establish the second.
Heb 10:10 And by that will we have been sanctified through the offering of the body of Jesus Christ once for all.
Php 2:6 who, though he was in the form of God, did not count equality with God a thing to be grasped,
Php 2:7 but emptied himself, by taking the form of a servant, being born in the likeness of men.
Php 2:8 And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross.
He came in humiliation in order to not only fulfill the prophecies about Him, as well as the Law (breaking God's laws, even one, is sin and sin earns death--which is why all people die, because all people are sinners), but to die on a cross in the stead of sinners, taking the full wrath of the Father against sinners so that God's justice would be met and that people would be saved from His eternal wrath (because if you die in your sins, you remain in your sins and therefore in eternal damnation).
This is why Christmas is a reminder of what a blessing it was for Christ Jesus to come (as prophesied multiple times and in detail)--because really it was to die in the place of ill-deserving sinners so that they would be saved and glorify God for His abundant grace, forgiveness, love, eternal life, and all the things we have in Christ.