How many tears have been shed over the defection of literally millions of Catholics the last thirty years? Why have these people left the Church? It is, first of all, a mystery. We cannot peer into their heads or their hearts. Ultimately, they're responsible before God for their decisions. The Catechism, however, gives us some clues: "Ignorance of Christ and his Gospel, bad example given by others, enslavement to one's passions, assertion of a mistaken notion of autonomy of conscience, rejection of the Church's authority and her teaching, lack of conversion and of charity: these can be at the source of errors of judgment in moral conduct" (CCC 1792). The great majority of people who leave the Church do so because of moral faults. They're not ready to submit their sins to God and to the Church's judgment and mercy through the sacrament of penance. This unwillingness to ask God's forgiveness for having offended Him leads to rationalization and self-justification. Over time, this leads to a loss of the virtues of faith, hope and charity, which are necessary for eternal life.

So, how do we bring back stray Catholics? First, we should be praying for conversion of their hearts. If their hearts come back, their minds will follow. We also need to have a relationship of friendship with the potential revert. True friendship means sharing ourselves without reserve. For a Catholic, this includes sharing Christ and His Church. We have no axes to grind, ulterior motives or hidden agendas. We don't come to judge, condemn, analyze or disdain. Rather, our goal is to help our friend find eternal life. Perhaps the first approach to bring the fallen away Catholic back is to ask, in a friendly manner, why he left the Church in the first place. We know, of course, there's no such thing as a "good reason" to leave the Church. There are plenty of bad ones, however, and your friend will provide a few.

You must be sympathetic and understanding while at the same time, uncompromising in your defense of the Gospel and the teachings of the Church. Once you've heard him out, you can begin to address his problems or objections. Rely on the Holy Spirit here. You want to be able to convincingly "account for the hope that is in you" (1 Peter 3:15). This may well involve your own study of the particular teachings of the Church to which your friend objects.

However, the ability to answer your friend's doctrinal questions will probably not be sufficient to bring him back. There is something else, just as important. He needs to see that you're a happy, well-adjusted Catholic. By observing your prayer, frequent confession and Mass, and Scripture reading, he'll notice the connection between the interior and exterior life of a Catholic — and how the sacraments work in both. You may have to gradually reintroduce him to Catholic sacramental and liturgical practice. Bring him to Mass, make a visit to the Blessed Sacrament, explain the meaning of Catholic customs and sacramentals to him. He probably never understood these Catholic practices in the first place.