The Word became flesh....

David Mathis at Desiring God begins a series of Advent posts about the incarnation.

The incarnation refers literally to the in-fleshing of the eternal Son of God—Jesus becoming a human being. The doctrine of the incarnation says that the eternal second person of the Trinity took on humanity in the person of Jesus of Nazareth. A helpful way to remember the key aspects of the incarnation is John 1:14: “The Word became flesh.”

He goes on to expand on the meaning of each of the words in that verse, "The Word," 'became," and "flesh" and summarizes by saying

So the eternal Son of God, without ceasing to be God, took on a fully human nature. This is the incarnation. (read it all)

Advent and the Incarnation :: Desiring God Blog