Luke 2:4.
So Joseph also went up from the town of Nazareth in Galilee to Judea, to Bethlehem the town of David, because he belonged to the house and line of David.
Matthew traces Joseph’s family tree all the way back to David. And Luke does the same thing for Mary’s family. That would make Jesus the son of David. That would make Him a king.
That’s one thing the angel told Mary when he told her she would have a baby: He will be great and will be called the Son of the Most High. The Lord God will give him the throne of his father David, and he will reign over the house of Jacob forever; his kingdom will never end.”
Both Joseph and Mary were from the royal family. And, in a sense, we are too. But something better than a son of David.
We are the sons and daughters of God.