What's meant by 'rendering to Caesar'?

I’ve been struck by two thoughts lately, one thought expands on my April 1 post concerning the political leanings of Jesus, the second asks to what extent faith and politics can or cannot accompany each other. It may not be fashionable to say, but it is certainly true; you can legislate morality. In fact I'd actually contend that every law adopted from seat-belt laws to smoking bans to insurance mandates is morality codified, heck the most morally telling law we pass is the budget – “where your treasure is, there your heart will be also” (Matthew 6:21). When I say that we can legislate morality, and then I give the examples above, I am not talking about philosophical morality but rather, I mean that we can "impose by law our moral code on others and make them behave as we expect." It is far more difficult, maybe impossible, to use the force of law to compel the conscience of someone else to believe as we do. Society creates and encourages behavior it deems moral precisely through the force of law, but we cannot – and do not expect our laws to change the heart of another person. We can stop a man from murder, but we cannot stop a man from thinking murderous thoughts.

From birth through death we are constantly searching for who we are, and our individual identity - how we see ourselves - is closely tied to who we are in community and how we live our lives in relation to others. Our relationships with each other and with the greater community around us shape who we are and how we see ourselves. How we choose to be involved in the lives around us often defines us not only in the eyes of others, for a man is known to those around him by his actions, but also defines us to ourselves, for who but God knows our hearts and minds as well as we do. In other words, how I see myself is determined by what I do.

So what about political involvement? As an individual in relationship to Christ as well as to one’s fellow man, politics would seem a natural extension of living in a community. For Christians, there is some good in being politically involved, but that is not the good, or even the key ground to fight over in this world. What is Good is to live lives that draw others to Christ - and draw ourselves ever closer at the same time. Some good comes from politics and social action, and from pursuing and advocating for policies that strengthen the moral fabric of society - the founding ethics of biblical Christianity and Judaism.

To live Christianly, to have my actions truly reflect my heart, must lead to some difference in our world, some "rendering unto Caesar.” It's important to create laws that protect the innocent and punish the guilty, it is important to vote, and to use our God-given freedom to create a country that seeks liberty and justice, a country that loves and encourages what is right and true. But more than working to affect the country, Christians must realize that it is when Christians seek to act like Christ that they most inspire their community. It is the heart that influences one to follow laws, though laws will always be necessary.

I guess my point is that people don't find that out by simply following laws.