“David thus calls him Lord, so how is he his son?" Jesus pointed out that the prophetic psalms called the Messiah King David’s descendant and his Lord. Jesus was correcting the common view of the Messiah and his kingdom. Many people wanted a Savior who would be a political hero (v21-25), while others were calculating how to build their power and possessions (arguing over “ownership” of a wife in heaven, v33). But Jesus said the Messiah was the Lord, the Life-giver.
“Now he is not God of the dead, but of the living, for all live to him" (v38). When we give up our small and selfish ideas and follow Jesus, we discover a new world, real Life.