When asked, "What's wrong with the world?" G.K. Chesterton famously replied simply, "I am." We want to be happy and yet we often seem to be the source of our own unhappiness, as well as that of others. Even when that is not the case, our lives—as blessed as they may be —have their share of sadness and disappointment. How do we respond? Do we become cynical and try, at all costs, to get as much pleasure as we can? Or do we recognize we were made for more?

In this classic work, Fulton Sheen explains the secret of authentic happiness: being spiritually remade. A genuinely spiritual life, Sheen contends, consists in more than obeying a set of commands, reading the Bible, or even following the example of Jesus. Before all else, it consists in being recreated and incorporated into a new, higher kind of life—the supernatural life of grace—and in being brought into a new kind of spiritual relationship, as a child of God through Jesus Christ.

What does it mean to be a Christian? Christianity is not a system of ethics; it is a life. It is not good advice; it is divine adoption. Being a Christian does not consist in just being kind to the poor, going to church, singing hymns, or serving on parish committees, though it includes all of these. It is first and foremost a love relationship with Jesus Christ.