“Who, for us and for our salvation, came down from heaven, and was incarnate of the Holy Spirit and the Virgin Mary, and was made man.”
Jesus was in heaven before being born, so he “came down from heaven.” Why? “For us and for our salvation.” Humanity could be saved in no other way, but through the incarnation of Jesus.
He was “was incarnate of the Holy Spirit and the Virgin Mary.” I am not sure why people have such a problem with the virgin birth (parthenogenesis). To me, this is a small miracle compared to creating the universe.
The metaphorical point of the Virgin birth is that Jesus was special. His birth was special. His mission was special. The metaphorical meaning is essential, the literal meaning is non-essential.
And “was made man.” A fancy word for God becoming man is hyperstatic union. This is a great mystery. And the church has never been dogmatic about it.