What does Luke 20:23 mean?

Jesus is on the Temple Mount teaching a crowd. Someone shows Him honor by saying, "Teacher, we know that you speak and teach rightly, and show no partiality, but truly teach the way of God" (Luke 20:21). Then he poses the question: "Is it lawful for us to give tribute to Caesar, or not?" (Luke 20:22). That is, is it consistent with the Mosaic law to pay the census tax to the Romans?

This style of philosophical discussion with a rabbi was common in Jesus' era. Examples of these debates are recorded in the Gemara: an important work of Jewish writing preserving varied interpretations of the Torah and the Oral Law. The text is something like commentary, theological discussion, debate, and a modern blog rolled into one.

The flattering opening and the philosophical question seem to invite Jesus to speak freely—even carelessly. But Jesus knows what's happening. The questioner is a plant. The scribes and chief priests are angry at Jesus' suggestion that God will destroy them if they kill Him (Luke 20:9–18). The questioner is a disciple of the Pharisees (Matthew 22:15–16). He isn't asking for a benign, lively debate; he's trying to trap Jesus.

If Jesus seems to endorse the Roman tax, the crowd will react as if He approves of the occupation of Judea and Galilee. If He says it's not good to give tribute to Caesar, He's encouraging the Jews to break the Roman law. In one case, He alienates the people. In the other, He's at risk of being arrested. The religious leaders would be happy either way.

Jesus knows this isn't a true-or-false question, however. The Jews owe taxes to the civil authority God has placed over them: the Romans. But they owe something to God, too, which is not contrary to that obligation. They need to pay both debts (Luke 20:24–25).