“Christ was God, and is God, and will forever remain God. He was not the Father, nor the Spirit, but the Son, the own, only-begotten, beloved Son of the Father.
And it was not the Divine being, neither the Father nor the Spirit, but the person of the Son who became man in the fulness of time. And when He became man and as man went about on earth, even when He agonized in Gethsemane and hung on the cross, He remained God’s own Son in whom the Father was well pleased (had all His pleasure).
It is true, of course, as the apostle says, that Christ, being in the form of God, did not think it robbery to be equal with God, yet made Himself of no reputation and emptied Himself (Phil. 2:6–7).
But it is a mistake to take this to mean, as some do, that Christ, in His incarnation, in the state of humiliation, completely or partly divested Himself of His Divinity, laid aside His Divine attributes, and thereupon in the state of exaltation gradually assumed them again.
For how could this be, since God cannot deny Himself (2 Tim. 2:13), and as the Immutable One in Himself far transcends all becoming and change? No, even when He became what He was not, He remained what He was, the Only-Begotten of the Father.
But it is true that the Apostle says that in this sense Christ made Himself of no reputation: being in the form of God, He assumed the form of a man and a servant.
One can express it humanly and simply in this way: before His incarnation Christ was equal with the Father not alone in essence and attributes, but He had also the form of God.
He looked like God, He was the brightness of His glory, and the expressed image of His person. Had anyone been able to see Him, he would immediately have recognized God.
But this changed at His incarnation. Then He took on the form of a human being, the form of a servant. Whoever looked at Him now could no longer recognize in Him the Only-Begotten Son of the Father, except by the eye of faith.
He had laid aside His Divine form and brightness. He hid His Divine nature behind the form of a servant. On earth He was and He looked like one of us.”
–Herman Bavinck, Our Reasonable Faith or The Wonderful Works of God (trans. Henry Zylstra; Grand Rapids, MI: Wm. B. Eerdmans Publishing Company, 2016), 305-306.