When Jesus tells the Pharisees and Herodians in the Gospel of Matthew (22:21) to “render unto the Caesar the things that are Caesar’s and to God the things that are God’s,” he sets the framework for how we should think about religion and the state even today. Caesar does have rights. We owe civil authority our respect and appropriate obedience. But that obedience is limited by what belongs to God. Caesar is not God. Only God is God, and the state is subordinate and accountable to God for its treatment of human persons, all of whom were created by God. Our job as believers is to figure out what things belong to Caesar, and what things belong to God — and then put those things in right order in our own lives, and in our relations with others.
. . . As Christians, we can’t claim to love God and then ignore the needs of our neighbors. Loving God is like loving a spouse. A husband may tell his wife that he loves her, and of course that’s very beautiful. But she’ll still want to see the proof in his actions. Likewise if we claim to be “Catholic,” we need to prove it by our behavior. And serving other people by working for justice, charity and truth in our nation’s political life is one of the very important ways we do that.
The “separation of Church and state” does not mean – and it can never mean – separating our Catholic faith from our public witness, our political choices and our political actions. That kind of separation would require Christians to deny who we are; to repudiate Jesus when he commands us to be “leaven in the world” and to “make disciples of all nations.” That kind of radical separation steals the moral content of a society. It’s the equivalent of telling a married man that he can’t act married in public. Of course, he can certainly do that, but he won’t stay married for long.