Although I spend the majority of my time defending the teachings of the Church on life, marriage, and sexuality, I know that facts, evidence, and arguments will not win the battle. My work encourages the faithful, but those without faith are easily led by the media. The only way the truth will prevail is if the number of converted souls increases.

Activism is not enough. Evangelization -- preaching the Gospel -- is the foundation on which we must build a truly just society.

Evangelization in a post-Christian age is not easy, because many people call themselves Christian as a sort of default position. They have a vague belief in God and see themselves as 'good' people. They aren't atheists, Muslims, or Jews, so they must be Christians. As babies they had been baptized, they have received some CCD or Sunday school, attended Mass, but they have never really been converted. The words they heard, never really penetrated. The responses they made didn't come from the heart, and so gradually they drifted away and when the world rejected the truth about the human person as proclaimed by the Church, they went along with the world.

They may have inherited a great Catholic tradition, but regarded it as the younger generation regards grandmother's sterling silver, something that takes up space, but is never taken out and used.

God has no grandchildren. Each one of us must become a child of God by adoption on our own. We can inherit practices and traditions, but we cannot inherit the faith. What makes evangelization of these 'grandchildren' hard is that they don't know what they are missing. They think that what they have is all there is.

We can speak with clarity to those who have never heard of Christ. We can proclaim to them the good news that Jesus of Nazareth is the only begotten son of God, that his passion and death are the full payment for sin, and that through faith in him our sins are forgiven and our salvation assured, and that he is present in the Holy Sacrament of the Eucharist. But how do we speak to the hearts of those who think they already know it all, and don't think they need to be converted? How do we call them to give their hearts to Christ? This is our task.

First of course, we must renew our own conversion, for it easy to grow cold or worse, lukewarm, to let our prayer become mere words. We really have to believe that those we want to hear the message need to hear it and will be blessed by it.

Most of us begin with our families, particularly our children. It is not enough to force them to go to Mass or demand outward obedience, we must pray for their conversion, which cannot be forced or a matter of obedience. Some parents say, "When you live under my roof, you will...," but the message the child hears is "When I no longer live under my parents' roof, I won't."

We must pray for our children's conversion, not just to keep them out of trouble, but for a true change of heart. We must speak to them clearly about Jesus, and we must give them the freedom to choose, because each soul must come willingly to Christ.

Our evangelism should not stop with our immediate family. We need to pray for friends, co-workers, even strangers that cross our path. Of course, we must give the witness of our lives, for if we want people to be attracted to Christ, we must show evidence of how faith in him has changed us. Prayer and witness are important; however, at some point we are going to have to present the Gospel. People cannot believe if they have not heard, and how can they hear if no one speaks, no one clearly and explicitly lays out the salvation message for them. We can't rely on the priest to do this. The unconverted need to hear it from us.

Sometimes this can be very difficult for Catholics, but it shouldn't be. When we were confirmed, we received the Holy Spirit and the Spirit knows exactly which words can touch the heart of another soul. If we have prayed, the opportunity will present itself for us to speak and the Holy Spirit will give us the words we need.

Only when hearts are changed, can we change the world.

Dale O'Leary is a freelance writer and author of "The Gender Agenda: Redefining Equality" and "One Man, One Woman."