The difference between true and false religion.
It is commonly agreed that to live without religion is to live in real misery and to be in no way better than wild animals. This being so, no one will want to be considered as being entirely indifferent to personal religion and the knowledge of God.
But there are many differences in the visible form that religion takes. This is because the majority of men are not really affected by the fear of God. Nonetheless, willingly or not, they cannot escape from the idea that there is some divine being whose power either holds them up or brings them down. This idea keeps coming back to their minds.
In addition, because their estimate of God is governed by the foolish and thoughtless conceit of their own mind, and not by His infinite majesty, they actually turn away from the true God. This is why, even when they make real and careful efforts to serve God, it turns out to be a waste of time. It is not the eternal God they are worshiping, but rather the dreams and illusions of their own hearts.
Now there is a fear which would most willingly flee from the judgment of God but which, being unable to do so, dreads it more than ever. True godliness does not lie here. It consists, rather, of a pure and true zeal which loves God as a real Father and looks up to Him as a real Lord; it embraces His righteousness and detests offending Him more than it does dying.
And all those who have this zeal do not set about rashly fabricating a god in line with their own wishes. Instead they seek the knowledge of the true God from God Himself, and do not conceive of Him as being different from what He reveals Himself to be and what He makes known to them.
John Calvin, Truth For All Time, 1537