"Christ Jesus: Who, being in the form of God, thought it not robbery to be equal with God: But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men." (Philippians 2:5-7)
The entire gospel message runs counter to the human mind. The Creator dying for the creation. The judge paying the penalty for the guilty. The immortal One dying. Sinless God substituting for human sinners. No human or devil ever could have thought of this scheme, and indeed, no such one did. This is evidenced by the works-oriented salvation offered by all cults and false religions, as conjured up by such sources.
But make no mistake! The babe in the manger was the Creator, holy and eternal! "Who is the image of the invisible God, the firstborn of every creature. . . . All things were created by him, and for him: . . . that in all things he might have the preeminence. For it pleased the Father that in him should all fulness dwell; And, having made peace through the blood of his cross, by him to reconcile all things unto himself" (Colossians 1:15-20).
In order to qualify as a sacrificial substitute, He had to be born as a child into humankind, but without the inherited sin nature of His human parents. A virgin birth was therefore necessary.
He had to live a sinless life. He had to be fully human, but also fully God, so that His substitutionary death could apply to the sins of more than one guilty sinner. He had to be "God with us," the meaning of the precious title Emmanuel (Matthew 1:23), as prophesied years before (Isaiah 7:14). JDM
Christ, by the highest Heav'n adored, Christ, the everlasting Lord:
Late in the time behold Him come, Offspring of a virgin's womb.
Veiled in flesh the Godhead see, Hail th'incarnate Deity!
Pleased as man with men to dwell, Jesus our Emmamuel.
Hark! the herald angels sing, "Glory to the newborn King!"