Public witness on issues of public concern is natural for Catholics because we have a commitment to the common good and to the dignity of each human person. Those two pillars -- the common good and the dignity of every human person -- come right out of Scripture. They underpin all of Catholic social thought. That includes politics. Politics is where the competing moral visions of a society meet and struggle. And since a large majority of American citizens are religious believers, it makes sense for people and communities of faith to bring their faith into the public square.

As a result, if we believe that a particular issue is gravely evil and damaging to society, then we have a duty, not just a religious duty but also a democratic duty, to hold accountable the candidates who want to allow that evil. Failing to do so is an abuse of responsibility on our part, because that's where we exercise our power as citizens most directly -- in the voting booth.

The "separation of Church and state" can never mean that religious believers should be silent about legislative issues, the appointment of judges or public policy. It's not the job of the Church to sponsor political candidates. But it's very much the job of the Church to guide Catholics to think and act in accord with their faith.

So since this is an election year, here are a few simple points to remember as we move toward November.

"Catholic" is a word that has real meaning. We don't control or invent that meaning as individuals. We inherit it from the Gospel and the experience of the Church over the centuries. If we choose to call ourselves Catholic, then that word has consequences for what we believe and how we act. We can't truthfully call ourselves "Catholic" and then behave as if we're not.

Being a Catholic is a bit like being married. We have a relationship with the Church and with Jesus Christ that's similar to being a spouse. If a man says he loves his wife, his wife will want to see the evidence in his fidelity. The same applies to our relationship with God. If we say we're Catholic, we need to show that by our love for the Church and our fidelity to what she teaches and believes. Otherwise we're just fooling ourselves. God certainly won't be fooled.

The Church is not a political organism. She has no interest in partisanship because getting power or running governments is not what she's about, and the more closely she identifies herself with any single party, the fewer people she can effectively reach.

Scripture and Catholic teaching, however, do have public consequences because they guide us in how we should act in relation to one another. Again, Catholic social action, including political action, is a natural byproduct of the Church's moral message. We can't call ourselves Catholic, and then simply stand by while immigrants get mistreated, or the poor get robbed, or -- even more fundamentally -- unborn children get killed. If our faith is real, then it will bear fruit in our public decisions and behaviors, including our political choices.

Each of us needs to follow his or her own conscience. But conscience doesn't emerge miraculously from a vacuum. The way we get a healthy conscience is by submitting it to God's will; and the way we find God's will is by listening to the counsel of the Church and trying honestly to live in accord with her guidance. If we find ourselves frequently disagreeing, as Catholics, with the teaching of our own Church on serious matters, then it's probably not the Church that's wrong. The problem is much more likely with us.

In the end, the heart of truly faithful citizenship is this: We're better citizens when we're more faithful Catholics. The more authentically Catholic we are in our lives, choices, actions and convictions, the more truly we will contribute to the moral and political life of our nation.

Archbishop Charles J. Chaput is the Archbishop of Philadelphia.