An issue which bothers me is this, I know Jesus was conceived by a virgin. How then is he being linked in genealogy to Abraham and David if Joseph is not his father. Joseph, husband to Mary is also listed in this genealogy as giving legitimacy to the fact that Jesus as a man is a descendant of Abraham. It does not challenge my faith but it keeps on popping up as a question in my mind. Probably the devil trying to twist me around to doubt my faith. What can you say about it.
Jesus is a legal descendant of Abraham and David by virtue of his adoption by Joseph. He’s a blood descendant of David’s through His mother Mary who was also of the Tribe of Judah. That’s why the Lord’s genealogy is different in Luke (Mary’s) than it is in Matthew (Joseph’s). When the Bible says that Jesus is of the house and lineage of David, it’s referring to both these things. Here’s a link to a more complete answer to a similar question: Qualifying Jesus As Israel’s King