I am well aware of the response that can be made from the other side: why does that one and only God of yours, that great God, lord of all things and master of all people as you call him, permit such things to happen and not either avenge or protect his worshippers? Why are people who don’t worship him rich, powerful and happy, in power as magistrates and kings, holding those very worshippers of his in subjection to their own dominion and might? This too must have its explanation, so that no confusion remains. First, this is the reason why worship of God is thought to be ineffective: people are led astray by the way the immediate goods of this earth look, which are quite irrelevant to care of the soul. Because they see the just are without these things and the unjust amply provided, they conclude that worsihpping God is futile as they can’t see those goods in it, and they think too that worship of gods is sound, since their worshippers enjoy wealth, position and kingship. But people of that persuasion are not looking deeply enough into the point of human existence, which is totally spiritual, not physical. All they can see is the visible: the body, that is. Now the body, in being available to sight and touch, is weak, fragile and mortal. All its goods are things of desire and admiration—wealth, position and power, for instance—because they bring a physical gratification, and for that reason are as perishable as the body itself. Since the soul, in which alone man has his being, is not susceptible to sight, so neither can its goods be seen, and they have their being in virtue alone; for that reason the soul is bound to be as stable, consistent and lasting a thing as virtue itself is, and the good of the spirit has its being in virtue.
Divine Institutes, Book 5, 21.7-11