The two variant genealogies of Jesus in Matthew 1:1–16 and Luke 3:23–38 agree on the essential point that he was descended from King David through Joseph, the husband of Mary. To be the legitimate King of the Jews, Jesus had to stem from David through his human, patriarchal family tree. The question that puzzles the modern reader is: If Mary conceived Jesus of the Holy Spirit, without having had any carnal union with Joseph or any other man, how can Jesus the Son of God be descended from David or anyone else through Joseph?
Matthew and Luke assume that their narrative makes sense to their readers; the Evangelists were not trying to mystify or pose a paradox. Actually, the Davidic descent of God’s Son Jesus through Joseph, Mary’s husband, reflects a concept widely known and accepted by East Mediterranean people from at least the Bronze Age to Roman times.