That we often miss the message an author is trying to convey is proven in the way we traditionally interpret Jesus' key words in Sunday's Gospel (Mt 22: 15-21). "Repay to Caesar what belongs to Caesar and to God what belongs to God."
Most of us believe that, by this statement, Jesus divides all creation between God and Caesar: between church and state. He draws a line of demarcation between religious society and secular society, a line never to be crossed. The state doesn't get involved in church issues, and the clergy reciprocate by having nothing to do with politics. Though the church is superior to the state, it still expects the latter to take care of those needs the church doesn't meet.
It's a neat division, but there's one problem: We find it nowhere in the Bible. The Scripture authors look at God's creation as a whole unit. Yahweh works no less in the lives of kings than in the lives of priests. The authors simply aren't concerned with the separation of church and state. As a good Jew, Jesus could never divide God's creation between those two institutions.
Our misinterpretation begins with our lack of knowledge about ancient monetary systems. During Jesus' earthly ministry, the king or emperor actually owned all the money. That's why his image and name were on each coin. It belonged to him. He just permitted people to use it.
That presumption enables Jesus to escape the trap the Herodians (who work for Romans) and the Pharisees (who despise Romans) prepared to Him. In other words, if we have Caesar's coin in our pocket and Caesar asks for it back in taxation, we'd better give Caesar what belongs to Caesar.
Jesus probably throws in the last statement -- "Repay to God what belongs to God" -- to remind His followers to be more concerned about what they owe God than what they owe anyone else. In Jesus' mind, the Roman coin, the Jew in whose pocket it is, and the emperor whose image and name are stamped on it all belong to God. Wherever God is, God encompasses all.
It's this last point which motivates many of our faith ancestors. The more they experience God, the more they're forced to destroy the limits they place on God's presence and activity.
God and Cyrus
No one does this better than Deutero-Isaiah. He's convinced Yahweh is working in the life of a pagan, Gentile king who doesn't even know Yahweh. The first reading (Is 45: 1, 4-6) is the classic expression of his liberal belief: "Thus says Yahweh to His anointed, Cyrus, whose right hand I grasp, subduing nations before him and making kings run in his service, opening doors before him and leaving the gates unbarred....I have called you by your name, giving you a title, though you knew me not."
Notice the title Yahweh gives the Persian king: "anointed." That word in Hebrew is "Messiah;" in Greek, it's "Christ." More than five centuries before Jesus' birth, Deutero-Isaiah believes not only that this uncircumcised leader will free the Israelites from their Babylonian Exile, but that he is also the Messiah for whom people have been waiting for centuries.
With this in mind, it's ironic the second reading is from Paul's first letter to the Thessalonians; the earliest Christian writing we possess (I Thes 1: 1-15). In it, Paul reflects on the success of his far-out plan to offer Christianity to Gentiles without demanding they first convert to Judaism. Like Yahweh, Jesus breaks through the restrictions His first followers put on His risen ministry. Even non-Jews can experience the work of faith and labor of love and endurance in hope of our Lord Jesus Christ.
God's true followers are more concerned with extending than restricting.