And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth. — John 1:14

I heard a Jehovah's Witness say that once the Word became flesh, it stopped being divine, because it became flesh. This sounds ridiculous, because one is essentially stating that God stopped being God. Nevertheless, what does it mean that the Word became flesh? In what manner did the Word become flesh, and how can one argue that the Word did not stop being the Word simply because it became flesh?

Thank you.