“The Word became flesh and blood, and moved into the neighborhood. We saw the glory with our own eyes, the one-of-a-kind glory, like Father, like Son, Generous inside and out, true from start to finish.” (The Message).
So staggeringly new was this conception of God in a human form that it is not surprising that even in the Church there were some who could not believe it. What John says is that the word became sarx (σαρξ). Now sarx is the very word Paul uses over and over again to describe what he called the ﬂesh, human nature in all its weakness and in all its liability to sin. The very thought of taking this word and applying it to God was something that their minds staggered at. So there arose in the Church a body of people called Docetists.
Dokein (δοκειν) is the Greek word for to seem to be. These people held that Jesus in fact was only a phantom; that his human body was not a real body; that he could not really feel hunger and weariness, sorrow and pain; that he was in fact a disembodied spirit in the apparent form of a man. John dealt with these people directly in his First Letter. “By this you know the Spirit of God: every spirit which confesses that Jesus Christ has come in the ﬂesh is from God, and every spirit that does not confess Jesus is not from God. And this is the spirit of the antichrist” (1 John 4:2–3). It is true that this heresy was born of a kind of mistaken reverence which recoiled from saying that Jesus was really, fully and truly human. To John, it contradicted the whole Christian gospel.
It may well be that today we are often so eager to preserve the fact that Jesus was fully God that we tend to forget the fact that he was also fully human.
The word became ﬂesh—here, perhaps as nowhere else in the NT, we have the full humanity of Jesus gloriously proclaimed. In Jesus we see the creating word of God, the controlling reason of God, taking human nature upon himself. In Jesus we see God living life as He would have lived it if he had been a man.
"He wished to become one of our children in order to make us His Children" - Augustine