Mapleleaf is right, but I wonder if it is understood.
The Word was made (manifest) flesh. The Word became fulfilled in the flesh. Word came into reality in the flesh. NOT, the Word of God MORPHED or transmutated into flesh. There is a huge difference.
What Word was made manifest, or made flesh? Start from the beginning and every promise of the coming of Christ that can be found from
Gen. 3:15 and onward such as
Isa. 9:6 and many others, came into reality by His birth.
God was made manifest (became known) in the flesh...his Word came to pass in the flesh of a man.