Other than my wife, you have been my closest relative in the Lord. My question is regarding the Virgin Birth of Jesus our savior. My wife (a baby nurse practitioner) and I are trying to confirm that Jesus was placed in the womb of Mary. We believe that the entire person of Jesus (egg and sperm; i.e. zygote) was placed in her womb by the Holy Spirit (God). Luke 1:28-31 are the appropriate verses.
If God only put the sperm into her egg, the egg material would contain the sin from Mary. Jesus was without sin; so we think all the material that God provided was his, and Mary carried Jesus to birth. In other words, we think that Mary just carried the baby Jesus in her womb to term, but had no part in the Lord’s physiology.
Jesus had to be a biological descendant of King David’s in order to have a legal claim to David’s Throne (Luke 1:32). Since He had no earthly father, His mother had to provide this link. Mary was of the tribe of Judah and the family of David, being descended from David through his son Nathan (Luke 3:31). An obscure reference in Exodus 20:5 seems to indicate that the sin nature passes from the father only. This explains how Jesus could be fully man but with no sin nature.