All men suppress the knowledge of God and instead worship demons instead
13. Hence we must hold, that whosoever adulterates pure religion, (and this must be the case with all who cling to their own views,) make a departure from the one God. No doubt, they will allege that they have a different intention; but it is of little consequence what they intend or persuade themselves to believe, since the Holy Spirit pronounces all to be apostates, who, in the blindness of their minds, substitute demons in the place of God. For this reason Paul declares that the Ephesians were “without God,” (Ephesians 2:12,) until they had learned from the Gospel what it is to worship the true God. Nor must this be restricted to one people only, since, in another place, he declares in general, that all men “became vain in their imaginations,” after the majesty of the Creator was manifested to them in the structure of the world. Accordingly, in order to make way for the only true God, he condemns all the gods celebrated among the Gentiles as lying and false, leaving no Deity anywhere but in Mount Zion where the special knowledge of God was professed, (Habakkuk 2:18, 20.) Among the Gentiles in the time of Christ, the Samaritans undoubtedly made the nearest approach to true piety; yet we hear from his own mouth that they worshipped they knew not what, (John 4:22;) whence it follows that they were deluded by vain errors. In short, though all did not give way to gross vice, or rush headlong into open idolatry, there was no pure and authentic religion founded merely on common belief. A few individuals may not have gone all insane lengths with the vulgar; still Paul’s declaration remains true, that the wisdom of God was not apprehended by the princes of this world, (1 Corinthians 2:8.) But if the most distinguished wandered in darkness, what shall we say of the refuse? No wonder, therefore, that all worship of man’s device is repudiated by the Holy Spirit as degenerate. Any opinion which man can form in heavenly mysteries, though it may not beget a long train of errors, is still the parent of error. And though nothing worse should happen, even this is no light sin — to worship an unknown God at random. Of this sin, however, we hear from our Savior’s own mouth, (John 4:22,) that all are guilty who have not been taught out of the law who the God is whom they ought to worship. Nay, even Socrates in Xenophon, (lib. 1 Memorabilia,) lauds the response of Apollo enjoining every man to worship the gods according to the rites of his country, and the particular practice of his own city. But what right have mortals thus to decide of their own authority in a matter which is far above the world; or who can so acquiesce in the will of his forefathers, or the decrees of the people, as unhesitatingly to receive a God at their hands? Every one will adhere to his own judgment, sooner than submit to the dictation of others. Since, therefore, in regulating the worship of God, the custom of a city, or the consent of antiquity, is a too feeble and fragile bond of piety; it remains that God himself must bear witness to himself from heaven.
John Calvin-Institutes of the Christian Religion-Book I-Chapter 5-Henry Beveridge Translation