The virgin birth is by the Holy Spirit meaning that the essence of God’s miraculous working and spirit formed Jesus and continues in the human flesh existence of Jesus. https://biblehub.com/matthew/1-23.htm Here the first matter of importance is the holiness by which the virgin conceived and gave birth to the son of God Jesus - in this sense a son of God because it is a human conceived by miraculous means so called a son of a god yet not just by any spirit (Nephilim were conceived by angelic spirits Gen 6) but by the Holy Spirit so truly holy. Then the writer, Matthew, took the theme matter further to say that the essence of God Himself is therefore present in Jesus by this Holy Spirit virgin conception holy means in which He becomes flesh. So it is truly actualised that God is with these people to whom Jesus is born.
