"Of course, it is true that religion on a superficial level, religion that is untrue to itself and to God, easily comes to serve as the 'opium of the people.' And this takes place whenever religion and prayer invoke the name of God for reasons and ends that have nothing to do with him. When religion becomes a mere artificial facade to justify a social or economic system - when religion hands over its rites and language completely to the political propagandist, and when prayer becomes the vehicle for a purely secular and ideological program, then religion does tend to become an opiate. It deadens the spirit enough to permit the the substitution of a superficial fiction and mythology for this truth of life. And this brings about the alienation of the believer, so that his religious zeal becomes political fanaticism. His faith in God, while preserving its traditional formulas, becomes in fact faith in his own nation, class or race. His ethic ceases to be the law of God and of love, and becomes the law that might-makes-right: established privilege justifies everything. God is the status quo."
Thomas Merton (Contemplative Prayer, pp. 113)