What does Mark 12:16 mean?
A denarius is a coin that represents a day's wage for a laborer. In the parable of the laborers in the vineyard (Matthew 20:1–16), the land owner offers to pay laborers one denarius no matter when in the day they started working. The design of coin itself is scandalous to the Jews. The image of Emperor Tiberius is pressed into one side with the words "Tiberius Caesar Augustus, Son of the Divine Augustus." Meaning, the coin claims Tiberius is a demigod and his parents are gods of the emperor cult.More to Jesus' point, the image on the coins also infers that Emperor Tiberius is the legal owner of the coins. They are distributed under Caesar's authority, and he is responsible for their value. Any time the coins are used, Tiberius' authority is acknowledged. Jesus asserts that this is okay. It is well within the rights of a government to issue coins and collect taxes. It is within a private person's rights to use those coins and pay taxes.
This comment by Jesus is greatly enhanced by what He says next (Mark 12:17). If "bearing the image" of someone implies obligation, then coins bearing the image of Caesar are legitimately owed to Caesar. A life bearing the image of God, therefore, is rightfully owed to God (Genesis 1:27).
Paul reiterates Jesus' words to the Christians in Rome. He explains that secular rulers are servants of God, commissioned by God to enforce justice. As such, they are owed their taxes, and we are to pay what is owed (Romans 13:1–7). It is possible to give due respect to a God-established but ungodly civil government and worship God at the same time.