What should I say to convince someone that practicing religion isn’t a waste of time?
A good place to start is the problem of happiness. Every human being by nature desires his or her own happiness. As Thomas Aquinas writes, “To desire happiness is nothing else than to desire that one’s will be satisfied. And this everyone desires” (Summa Theologiae I-II:5:8).
But whatever satisfaction we receive from the goods that satisfy our wills is always subject to being undermined. Consider, for example, how easily bodily and material goods can be taken away from us. Many healthy people wake up and discover that they have a life-threatening illness, with only a few months to live. Natural disasters can take away our material goods in an instant. Can one really be content knowing that these evils could pop up any day?
There is also the looming threat of death. Any goods that we possess in this life will ultimately be lost, since “the living know that they will die” (Eccl. 9:5). I don’t think any sane person likes the idea that all the goods of this life could be wiped out at any moment by death.
Religion offers a solution to these various aspects of the problem of happiness in some way or another. And since every human being cares about his or her own happiness, he or she ought to care about religion. I will speak here only of the Christian religion.
Christianity says that there is an ultimate good for us to possess that can in no way be lost. That ultimate good is God himself, and full possession of him is to be had in heaven. And any goods that we lose in this life will not be missed, because God himself will completely satisfy the will’s desire. This experience of complete satisfaction, of happiness, is unending and free of all looming threats that could possibly undermine it.
Christianity also offers a solution to the problem of happiness with its teaching that Jesus Christ has conquered death. Even though man must die, he can live again with a glorified body in the new heaven and new earth on condition that he dies in friendship with Christ. And such life is forever, free from corruption and the threat of death.
The bottom line is that Christianity is important because it offers man the key to being man fully alive. It offers a complete and perfect state of happiness that is definitive and unending. And that hope for eternal life is such that Paul can say, “I consider that the sufferings of this present time are not worth comparing with the glory that is to be revealed to us."