The Pharisees plotted a way to trap [Jesus] into saying something damaging. They sent their disciples, with a few of Herod’s followers mixed in, to ask, “Teacher, we know you have integrity, teach the way of God accurately, are indifferent to popular opinion, and don’t pander to your students. So tell us honestly: Is it right to pay taxes to Caesar or not?”
Jesus knew they were up to no good. He said, “Why are you playing these games with me? Why are you trying to trap me? Do you have a coin? Let me see it.” They handed him a silver piece.
“This engraving—who does it look like? And whose name is on it?”
They said, “Caesar.”
“Then give Caesar what is his, and give God what is his.”
The Pharisees were speechless. They went off shaking their heads. (Matthew 22:15-22)
Jesus always got the better of his critics. The tax in question was the Roman poll-tax. The Jewish people despised it. In fact, a couple of decades before Jesus was asked about it, a popular leader from the Galilee area named Judas had led a major revolt against the Romans. For the Zealots, Judas and his revolt still inspired them to fight against Rome. So the question was very dangerous: supporting the tax meant siding with the Romans. But to oppose the tax would open up Jesus to the charge of sedition. No matter how he answered, the Pharisees figured they could get Jesus into serious trouble.
When Jesus asked them to show him a denarius, Jesus revealed their hypocrisy. If they really were the good, patriotic Jews they pretended, then how could they carry a coin with an idolatrous portrait of Caesar carrying an inscription that described him as the “son of God?” With his answer, Jesus distanced himself from the Zealots and indicated that loyalty to a pagan government was not incompatible with loyalty to God.
What Jesus told the Pharisees took the wind out of their sails. But notice that Jesus’ answer contradicted what his disciples would have expected of the Messiah. Though not everyone was a Zealot, most Jewish people believed in their goals and they all expected the Messiah to overthrow the occupiers.
The kingdom of God and the kingdom of Man are two different, and sometimes mutually exclusive things. Jesus thinks we can honor both God and whatever nation we live in.