I once had a discussion with a man who maintained that he wanted abortion to be rare; he was "personally opposed" you see, but didn't see the need to have a law against it. When I asked him why, if he thought abortion was wrong, he didn't see a need for a law preventing the murder of children in the womb, he mumbled something about "choice."
This same man professed a belief in Jesus Christ, and attended services at his church. For him, Christianity is something he does for an hour or so on Sunday morning. To me the beliefs he espoused were incompatible because Jesus is not a hobby — Jesus is Lord.
I have a term for people who follow Jesus on some things but not others: part-time Christians. Part-time Christians believe they can modify the Christian faith to suit their needs, or discard some articles of faith altogether, by rationalizing their selection in any number of ways. They will rationalize that "society is secular, therefore my faith must be private," or "the Church has no right to tell me what to do in my bedroom." As if Jesus' teachings could be sorted through like old clothes.
We are commanded by our Lord to "go and make disciples of all nations," not "lock your doors and hope someone comes by." Christians have a duty to participate in society and be salt and light to the others. If we simply cede the public square, we are abandoning our baptismal promises and squandering the gifts the Spirit granted us. As recipients of the fullness of the Gospel, Catholic politicians have a specific and grave responsibility to live out their faith in the public square. From him to whom much is given, much is expected.
A full-time Christian politician allows Jesus to inform and guide his life and decisions. This does not mean establishing theocracy; it does mean ensuring the support of laws that are consistent with Christian teaching in the areas of social justice, morality, and natural law. Part-time Christians hide behind their uninformed conscience to avoid decisions, or even to make politically expedient decisions contrary to their profession of faith. To the part-timer, faith is a badge to be worn to garner votes rather than a way of life.
The same is true for those who assert the Church has no authority past the threshold of their home. The part-time Christian maintains that he can do whatever he pleases if "it feels right" or "harms no one else." This is the rationale many use for immoral sexual behavior or using contraceptives. The part-time Christian doesn't see a connection between what is done in privacy and a relationship with God. Frankly, this is a pagan way of thinking. It's the pagans, not the Christians, who believe they can hide something from God; and it's the pagans who refuse the lordship of Christ over their lives.
To put it bluntly, either Jesus is Lord of your life or He is not.
The Catechism answers the part-time Christian with this paragraph: The faithful should "distinguish carefully between the rights and the duties which they have as belonging to the Church and those which fall to them as members of the human society. They will strive to unite the two harmoniously, remembering that in every temporal affair they are to be guided by a Christian conscience, since no human activity, even of the temporal order, can be withdrawn from God's dominion." (#912)
The Second Vatican Council fathers (from whom the Catechism quotes above) made it clear that the Christian cannot separate his life into bits and parse them out between God and men…"no human activity…can be withdrawn from God's dominion." If we withhold parts of our bodies or parts of our minds from God, we sin against Him, rejecting His total Lordship over us.
We aren't expected to be perfect, but we are expected to try to be. Our Lord reminded us over and over again that our love and friendship with Him must be manifested in our lives, "If you love me, you will keep my commandments" (Jn 14:15)
Jesus is Lord…let Him be your Lord today.