From the Reformer
Further, when he says that “the fullness of the Godhead dwells” in Christ, he means simply, that God is wholly found in him, so that he who is not contented with Christ alone, desires something better and more excellent than God. The sum is this, that God has manifested himself to us fully and perfectly in Christ.
Interpreters explain in different ways the adverb bodily. For my part, I have no doubt that it is employed—not in a strict sense—as meaning substantially. For he places this manifestation of God, which we have in Christ, to all others that have ever been made. For God has often manifested himself to men, but it has been only in part. In Christ, on the other hand, he communicates himself to us wholly. He has also manifested himself to us otherwise, but it is in figures, or by power and grace. In Christ, on the other hand, he has appeared to us essentially. Thus the statement of John holds good: “He that hath the Son, hath the Father also.” (1Jn 2:23.) For those who possess Christ have God truly present, and enjoy Him wholly.
—John Calvin, Commentary on Philippians, Colossians, and Thessalonians
Pulling It Together
It is a mystery worth contemplation: Jesus was not just a sinless, perfect human. He is God. Fully God. God did not use him as some recepticle that he filled for a brief period of time and left. Jesus was God at his human inception. He was still God when he taught in the temple and played with his friends. He was God when he taught his disciples and suffered under Pontious Pilate. He was God when he was crucified and died. He was God when the Father and the Spirit resurrected him. And he is still God. This Living Logos, this Creative Word who came down among us is at once fully man and fully God. Do not allow anyone to “plunder” (from Calvin’s above-quoted Commentary) you with any other vain teaching.