Intro to Chapter 3: The God-Man.
Christianity holds that it is a mistake to think of Jesus as half-man, half-God, like one of the demigods of mythology. He was, and is, completely human and completely God, a man with all of God’s nature, and God with all of man’s. This God-man had two complete natures, and yet was one person. The Second Person of the Trinity was Mary’s son. Mary’s son was God.
At the wedding at Cana, Jesus’ two natures were both on display. Mary addressed him as her son, but asked him for the impossible. There were two ways for Jesus to make wine. Using the powers of his human nature, he could have begun to tread grapes, but in the middle of a wedding feast this would be impractical at best. Using the powers of his divine nature, he could have done what the apostle John records him as doing. Jesus was one person with the powers of both natures at his disposal, but at the wedding feast there had been as yet no public display of his divine nature.