What does Matthew 22:21 mean?

Though Jesus knows the challenge is a feeble attempt by the Pharisees to trap Him, He is answering a supposedly no-win question: Is it lawful to pay taxes to Caesar (Matthew 22:15–20)? He has asked for a denarius, the coin required to pay the tax, and has asked whose image and inscription are on the coin. Everyone present would have known this, even without looking at the coin. The denarius was a required currency in Israel. Some quickly answered that Caesar's name and inscription were on the coin. Specifically, the image was of "Tiberius Caesar, son of the Divine Augustus." By this time, though, the word Caesar had become a title, meaning emperor of Rome and its occupied territories throughout the world.

Jesus now gives a masterful reply to a trick question: Give to Caesar what is Caesar's and give to God what is God's.

In other words, that which bears the image of Caesar ultimately belongs to him. Why not give it to him? In this way, Jesus essentially shrugs off the challenge as a false dilemma. One can honor the requirements of a secular government (Romans 13:1) without embracing all it stands for. Paying the tax to Rome, then, is a separate question from the issues of the Old Testament law.

Interestingly, Jesus' remark also begs an important question: if we owe Caesar that which bears his image, what then do we owe God? The assumed answer is that we owe God that which bears the image of God. This profound implication points to the creation account, where God created humanity in His own image (Genesis 1:27). Every human being bears the image of God. In that way, all of humanity belongs to Him, including ourselves. Jesus' answer makes clear that human beings are responsible not just to give their money to whatever government issues it, but also to give ourselves to the God who made us.