A shoot shall come out from the stock of Jesse,
and a branch shall grow out of his roots.
The spirit of the Lord shall rest on him,
the spirit of wisdom and understanding,
the spirit of counsel and might,
the spirit of knowledge and the fear of the Lord.
His delight shall be in the fear of the Lord.
- Isaiah 11:1-3a
You search the scriptures because you think that in them you have eternal life; and it is they that testify on my behalf. Yet you refuse to come to me to have life.
- John 5:39-40
There were those who wouldn't accept Jesus' messianic credentials unless he was descended from David, as Isaiah had foretold many centuries before. For the gospel writers, there was a way to handle those people: give them what they want. Jesse was the father of David, the greatest of Israel's kings. According to the gospels, Joseph was descended from David. Kind of funny, though: if Mary was a virgin and conceived Jesus through the Holy Spirit, Joseph was Jesus' stepfather.
Go, stepdads! You have a high calling from a truly honorable forerunner.
People use the Bible in all sorts of interesting ways, trying to predict the future, trying to get one step ahead of God, trying to justify what they are already doing, seeking reassurance that they are not too far off track. I'm sure I do it my fair share, too.
Here's a funny conundrum, then: If Jesus was born of a virgin, then he wasn't genetically descended from David. If he was genetically descended from David, then he wasn't born of a virgin. Puzzle that one out for a while. Are the gospel writers giving us a clever poke in the eye, or is God making fun of our urge to trust in the Bible more than we trust in God?
So Jesus was grafted onto David's line, but only for the sake of appearances. There was no genetic need for the Messiah to have this pedigree, because God is not bound by the Bible.
It's a creative and generous solution, isn't it? Let the scripture-searchers have what they want. If they need Jesus to be descended from David, and if they're not going to think about it too deeply, so be it. Luke is less cagey about it than Matthew. He writes: "Jesus was about thirty years old when he began his work. He was the son (as was thought) of Joseph son of Heli" (3:23).
As was thought!
The Bible does not grant eternal life; it only points to it. It is there to open up the conversation, but don't let the path become the destination.
It is not our genealogy that gives us our true name. No matter who you are, or the circumstances of your birth, or the behavior of your parents and grandparents, the source of your worthiness is the divine Love that created you and loves you more deeply than you can possibly imagine. Trust in that love.