In his contribution to Joy and Human Flourishing, Jurgen Moltmann observes that modern theories of religion trace it to “misfortune.” Marx is representative: “Religion is the sigh of the oppressed creature.” Religion must be useful, must meet a need, “because everything in the modern world must be necessary; otherwise it is superfluous and useless.”
Moltmann doesn't buy it: “this view is wrong. In truth, religion is the feast of life, useless but joyful, and prayer is praise for the fortune of being.” Religion arises not from lack but from fullness; not from need but from satisfaction in life.
“Primitive religions” follow the rhythms of nature and of human existence, and in them Moltmann finds “a human echo of God’s pleasure in his creation? The glorification of God lies in any case in the festive demonstration of the human joy of existence. Human beings in their fondness for this finite life and by their affirmation of mortal beauty share in the infinite pleasure of the Creator of this world.”
The error is the basic one of thinking that religion must be necessary. Moltmann thinks it's “not necessary but very meaningful and liberating to express the joy of existence in praise, thanksgiving, singing, and dancing and to find the right bodily and sensuous forms.” And this loops back into fuller life: “The feast of life gives wings to the soul and new energies to the body. It is renewing life out of the transcendent origin of life.”