CCC 1718 The Beatitudes respond to the natural desire for happiness. This desire is of divine origin: God has placed it in the human heart in order to draw man to the One who alone can fulfill it:
We all want to live happily; in the whole human race there is no one who does not assent to this proposition, even before it is fully articulated.1
How is it, then, that I seek you, Lord? Since in seeking you, my God, I seek a happy life, let me seek you so that my soul may live, for my body draws life from my soul and my soul draws life from you.2
God alone satisfies.3
1 St. Augustine, De moribus eccl. 1, 3, 4: PL 32,1312.
2 St. Augustine, Conf. 10, 20: PL 32, 791.
3 St. Thomas Aquinas, Expos. in symb. apost. I.