The Condescension of the King
God sending His only begotten Son into the world IS the humiliation of the King of Glory. But to understand why this is the case, it is necessary to understand what the Bible means when it says Jesus is "the only begotten Son of the Father."
“Who, being in the form of God” (Philippians 2:6) means that, prior to his birth in Bethlehem, the Second Person of the Blessed Holy Trinity existed from eternity “in the form of God” and “equal with God.”
To what does “only begotten” refer in the Gospel of John? Not to the human birth of Jesus in Bethlehem - His incarnation. Rather, “only begotten” refers to what theologians like Augustine termed “the eternal generation of the Son.”
The eternal generation of the Son means that the Second Person of the Blessed Holy Trinity receives His life from God the Father who receives His life from no one; and the Son receives this life from eternity so that there never was a time when the Son was not receiving His life from the Father.