Luke 20 records a series of tests. The chief priests, scribes and elders demanded to know by what authority Jesus acted. Jesus asked whether John's baptism was from heaven or from men. They feared both answers, so they gave none. Jesus' question exposed that their problem was not a lack of evidence but an unwillingness to submit to God.
In the parable of the vineyard, the owner sent servant after servant, and finally his beloved son. The tenants killed the son, hoping to take the inheritance. Jesus quoted Psalm 118: the stone which the builders rejected became the chief cornerstone. Israel's leaders would reject Jesus, but God would make Him the foundation of His people.
Spies asked if it was lawful to pay taxes to Caesar. Jesus said to give to Caesar the things that are Caesar's, and to God the things that are God's. Coins bear Caesar's image, but people bear God's image, so we owe our whole selves to God. The Sadducees then mocked the resurrection with a story of seven brothers. Jesus explained that resurrection life is different from this life. Moses called God the God of Abraham, Isaac and Jacob, so He is not the God of the dead, but of the living. Finally, Jesus asked how the Christ can be both David's son and David's Lord.