How can I be happy? 

Happiness is the stick by which we tend to measure the success of our lives, isn’t it? Even Saint Augustine admitted, “We all want to live happily; in the whole human race there is no one who does not assent to this proposition.” Yet many people seem to think that happiness is an accident of birth, or tied to particular circumstances or acquisitions, or even a goal to be pursued in itself. Scripture teaches that happiness is not a goal; it is a gift. God offers this gift through the works of creation, and we discover it ultimately in coming to know the Creator behind it all.

The biblical idea of happiness is linked to the word beatitude (Latin for “bliss”). We think first of the Beatitudes Jesus offers in his Sermon on the Mount in Matthew. Sometimes the primary word of each beatitude is translated as “blessed,” but a more literal rendering would be the cry, “Happy you!” The eight choices noted in Matthew’s list—including being just, pure of heart, merciful, a peacemaker—already find the chooser in a happy state. Because God is the source of human happiness, doing as God does automatically places us in the condition of bliss.

So the short answer to the question is: Happiness comes from living according to God’s will. Following God's will, in fact, is the only things that does; or as Saint Thomas Aquinas put it, “God alone satisfies.” It’s not for nothing that the word gospel literally means “good news.” Like any good news that comes to you, the gospel ought to make your day—or in this case, your lifespan and then some.

Saint Paul also lists joy as one of the nine fruits or by-products of the Holy Spirit. As Christians we carry the Spirit’s joy within us, and one way to tell is how joyfully we experience our lives. Saint Francis de Sales went so far as to warn against giving in to excessive sadness because it was counter to the life of faith.

That doesn’t mean that sadness is never appropriate; as the Book of Ecclesiastes says, there’s a time for everything under heaven. But clinging to moods does mean that we miss opportunities to demonstrate to others that the news of Christianity is, in fact, as good as advertised.

Scripture
Ecclesiastes 3:1-11; Matthew 5:3-11; Galatians 5:22-23

Audiotape
The Call to Christian Happiness, “talks on the shortest route to happiness,” by Sherry Weddell and Father Michael Sweeney, O.P., from the Catherine of Siena Institute, a nonprofit ministry of the Western Province of the Dominicans, http://shop.siena.org/. 

Books
Five for Sorrow, Ten for Joy by Rumer Godden (Loyola Press)
Surprised by Joy by C. S. Lewis (Harcourt Brace)