Now we need to answer the question, how can God become a man? How can the creator of the universe become human? Or as Bette Midler sang, “What if God was one of us?” Well, Bette He did become one of us.
For some people Jesus as fully God and fully man is a major problem. This is a huge stumbling block for Jehovah Witnesses. They cannot understand how one person can have two natures, divine and human; they think he was only a man. I will begin by looking at appearances of God in the Old Testament.
God visits the earth
- In the form of a man
The technical term is a “theophany.” God reveals Himself in some temporary outward, physical manifestation. In both the Old and New Testaments the appearances were usually a voice or a physical appearance. However, we must remember John 4 teaches that God is spirit. Therefore, when God appears in the Old Testament it is some sort of projection, a theophany; God is a non-physical being. In the Old Testament multiple times the appearance of God is referred to as “the Angel of the Lord,” though not the very substance of God Himself.  Many Christian scholars believe “the Angel of the Lord” is none other than the pre-incarnate Christ. What that means is Jesus made appearances before he was born to the Virgin Mary.
One example in the Old Testament was the Lord appearing to Abraham at the Oaks of Mamre. Genesis 18:1 “Now the LORD appeared to him by the oaks of Mamre, while he was sitting at the tent door in the heat of the day.” God in the form of a person discussed with Abraham the destruction of Sodom and Gomorrah. Other examples include Moses and the burning bush in Exodus 3:2 and Jacob wrestling with a “man” in Genesis 32:24-30.
In the Old Testament God visits the earth in the form of a man, but in the New Testament he primarily visits in substance, as a man in the flesh. We do have a few examples of a theophany New Testament: a voice and a dove at the baptism of Jesus (Matt. 3:16f), voice at transfiguration (Matt. 17:5), Stephen and Paul’s visions, and a few others. However, at the birth of Jesus Christ, this was not a theophany; he appeared in substance.
- In substance: We call this the incarnation. In Micah 5:2 it says Messiah or King or ruler was to be born in Bethlehem (His humanity), yet He was from everlasting to everlasting to everlasting (His deity).
Micah 5:2 [God is speaking] “But as for you, Bethlehem Ephrathah, Too little to be among the clans of Judah, From you One will go forth for Me to be ruler in Israel. His goings forth are from long ago, From the days of eternity.” God is going to bring forth an eternal ruler, implying He will be divine.
We see that ruler being born in Matthew 2:1-6: “Now after Jesus was born in Bethlehem of Judea in the days of Herod the king, magi from the east arrived in Jerusalem, saying, 2 ‘Where is He who has been born King of the Jews? For we saw His star in the east and have come to worship Him.’ 3 When Herod the king heard this, he was troubled, and all Jerusalem with him. 4 Gathering together all the chief priests and scribes of the people, he inquired of them where the Messiah was to be born. 5 They said to him, ‘In Bethlehem of Judea; for this is what has been written by the prophet: 6 AND YOU, BETHLEHEM, LAND OF JUDAH, ARE BY NO MEANS LEAST AMONG THE LEADERS OF JUDAH; FOR OUT OF YOU SHALL COME FORTH A RULER WHO WILL SHEPHERD MY PEOPLE ISRAEL.’” Here Matthew identifies this Messiah/ruler as Jesus. He would fulfill what Matthew 1:23 says about Him:23 “BEHOLD, THE VIRGIN SHALL BE WITH CHILD AND SHALL BEAR A SON, AND THEY SHALL CALL HIS NAME IMMANUEL,” which translated means, “GOD WITH US.” Clearly, Matthew is teaching through Jesus, God took on human flesh.
John 1:1,14 “In the beginning was the Word, and the Word was with God, and the Word was God [deity]….And the Word became flesh, and dwelt among us, and we beheld His glory [humanity]….” We call this stepping down to the rank of man the Kenosis.
 Source for some of the following content is from a teaching called “The Bible Fast Forward” by Greg Koukl.
 ISBE, Vol..4, p.829