Augustine said, “This is the happy life, to rejoice to Thee, of Thee, for Thee. . . . For they who think there is another, pursue some other and not the true joy.” 
The happy life is to worship God as God—and not put anything or anyone else in His place. But in this fallen world, we can’t simply affirm God as the source of happiness without dealing with the competition. Take a look at this list of potential idols. As I share in my book Happiness, all of them can be legitimate sources of happiness when enjoyed in their rightful position below God, but they become toxic when we elevate them above Him.
God isn’t listed because He’s the only one we can worship without committing idolatry. If God is at the center, almost anything on this list can help us enjoy happiness in Him.
We should remind ourselves, “Every good thing given and every perfect gift is from above, coming down from the Father of lights” (James 1:17, NASB). The problem with idols is not that they’re intrinsically wrong. God created wood, stone, and gold, which can be fashioned into heathen idols. Likewise, He created family, friendships, work, music, art, sex, food, drink, and all that we rightly value. But all of these can still become idols—God-substitutes.
Idolaters are condemned by God because “they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator” (Romans 1:25). Creation and creatures are not the problem; the problem is fallen human hearts that worship these false gods instead of the holy and happy God.
 Augustine, The Confessions of Saint Augustine, trans. Edward B. Pusey, book 10, chapter 22.