Adapted from the homily.
There are three "reasons" God became man. I'd like to discuss these, using Christmas gifts from my past to help illustrate.
1) Redemption. Jesus was born to redeem mankind. “He will save his people from their sins” (Matt 1:21). The separation between man and God due to the Fall could only be restored by God becoming man. My "saving" Christmas gift from childhood was snow pants. The gift was lame, I thought at first, but it allowed me to play in the snow and have fun without getting cold or wet.
2) Revelation. Jesus was born to reveal more about God. “The only Son, God, who is at the Father's side, has revealed him” (Jn 1:18). Jesus showed us that God is not just some generic force, but is a Trinity. God is relational, which means we can talk to him. A "revealing" Christmas gift from my past was a bunch of wood and tools. I went through a phase in high school were I thought I wanted to be a wood worker. By the end of January, having failed to make things, I realized this wasn't meant to be.
3) Righteousness. Jesus was born to show us how to live well. “For behold, I proclaim to you good news of great joy” (Lk 2:10). Loving one another as yourself and loving God is the key to happiness. The Christmas gift that brought me a lot of happiness was the video game MarioKart. It was fun to play individually and it brought people together, since you could play each other in battle mode.
If you open a gift this year that has a redeeming, revealing, or righteous quality to it, give thanks to Jesus.