Advent is my yearly reminder to brush up on Christology, the doctrine of the person of Christ. I’ve found it helpful to approach the subject under three headings:

1. Jesus as Lord (fully divine)
2. Jesus as Savior (fully human)
3. Jesus as Treasure (one person)

So here’s part one, with parts two and three on the way in the next couple days.

In this Christological triad (Lord-Savior-Treasure), Jesus’ Lordship is tied to his divinity and to him rightly being called Yahweh, the name surpassingly more excellent than angels (Heb. 1:4), the name above every name (Phil. 2:9). Here’s the connection between Lordship and the divine name.

Yahweh, the Lord

God’s personal name Yahweh, first revealed to Moses at the burning bush, was so sacred to the ancient Hebrews that they would not risk mispronouncing it by speaking it. So every time they came across the name while reading their Scriptures (our “Old Testament”), they would say Adonai, meaning Lord. So when the Greek translation of the Scriptures was produced, Yahweh was rendered Kurios (Greek for Lord), and so in “New Testament” times, Jesus being called Kurios had the effect of identifying him with the divine name Yahweh.

The divinity of Jesus is pervasive in the New Testament and so fundamental that it is usually assumed among first-century Christians, rather than argued for. But Jesus being called Lord may be the strongest way the New Testament ascribes divinity to Jesus. There are times where Jesus is called God, other times Son of Man has divine connotations, other times there are clear attributes of deity, but page after page Jesus is called Lord—and being so called, he is identified with God’s personal name.

The Incarnation

What we celebrate at Christmas is that Yahweh himself, the eternal God in the second person of the Trinity became man. We call this the incarnation, which refers literally to the in-fleshing of the Son of God—Jesus taking humanity to his person, being clothed, as it were, in human flesh. The doctrine of the incarnation teaches that the divine second person of the Trinity took on humanity in the person of Jesus of Nazareth, not by losing any of his divinity, but by adding humanity to himself. A helpful way to remember this heart of the incarnation—the divine adding the human—is John 1:14: “The Word became flesh.”

The Incarnation and the Cross

So the eternal Son of God, without ceasing to be God but remaining fully divine, took on full humanity. And what a magnificent doctrine and fuel for worship this is! Jesus didn’t just become man because he could. It wasn’t just a showoff move. He became man “for us and for our salvation” (in the words of Athanasius). The Word became flesh to save us from our sin and to free us to marvel at and enjoy the person in whom there is this unique union of divinity and humanity.

The incarnation is an eternal testimony that the fully divine Son and his Father are unswervingly for us.

Tomorrow we’ll look at Jesus’ full humanity.