That
"the Word was made flesh" does not mean that the nature of
God was changed into flesh, but that flesh was assumed by the Word
into the unity of His person. The word "flesh" moreover
signifies the whole man, with whom the Son of God so inseparably
united Himself within the womb of the Virgin, fecundated by the Holy
Spirit and destined to remain for ever virginal, that He who was
begotten of the essence of the Father before time, in time was born
of the Virgin's womb. For in no other way could we be released from
the chains of eternal death, except He become humble in our nature
who remained almighty in His own.
– Pope
Saint Leo the Great