From Commentary on Jeremiah (1559)
If a reason is given here why the prophet had bidden the heavens to be astonished and terrified, then we must render the words thus, “For two evils have my people done;” but I rather think that the preceding verse is connected with the former verses. The Prophet had said, “Go to the farthest lands, and see whether any nation has changed its gods, while yet they are mere inventions.” I think then the subject is closed with the exclamation in the preceding verse, when the Prophet says, “Be astonished, you heavens.” It then follows, “Surely, two evils have my people done,” even these, — “they have forsaken me,” — and then, “they sought for themselves false gods.”
When anyone forsakes an old friend and connects himself with a new one, it is an iniquitous and a base conduct: but when there is no compensation, there is in it united together, folly, levity, and madness. If I despise what I know to be profitable to me, and embrace what I understand will be to my hurt, does not such a choice prove madness? This then is what the prophet now means, when he says, that the people had sinned not only by departing from the true God, but also by going over, without any compensation, unto idols, which could confer no good on them.
He says that they had done two evils: the first was, they had forsaken God; and the other, they had fallen away unto false and imaginary gods. But the more to amplify their sin, he makes use of a similitude, and says that God is a fountain of living waters; and he compares idols to perforated or broken cisterns, which hold no water.
When one leaves a living fountain and seeks a cistern, it is a proof of great folly; for cisterns are dry except water comes elsewhere; but a fountain has its own spring; and further, where there is a vein perpetually flowing, and a perennial stream of waters, the water is more salubrious and much better. The waters which rain brings into cisterns are never so wholesome as those which flow from their own native vein: and when the very receptacles of water are full of chinks, what must they be but empty?
Hence then God charges the people with madness, because he was forsaken, who was a fountain and a fountain of living waters; and further, because the people sought unprofitable things when they went after their idols. For what is to be found in idols? some likeness; for the superstitious think that they labor not in vain, when they worship false gods, and they hope to derive some benefit. There are then some resemblances to the true in false religions; and hence the Prophet compares false gods to wells, because they were made hollow, suitable to hold water; but there was not a drop of water in them, as they were broken cisterns.
We now perceive what the prophet meant — that we cannot possibly be free from guilt when we leave the only true God, as in him is found for us a fullness of all blessings, and from him we may draw what may fully satisfy us. When therefore we despise the bounty of God, which is sufficient to make us in every way happy, how great must be our ingratitude and wickedness? Yet God remains ever like himself: as then he has called himself the fountain of living waters, we shall at this day find him to be so, except he is prevented by our wickedness and neglect. But the Prophet adds another crime; for when we fall away from God, our own conceits deceive us; and whatever may appear to us at the first view to be wells or fountains, yet when thirst shall come, we shall not find a drop of water in all our devices, they being nothing else but dry cavities.
John Calvin (1509-1564) was one of the most influential theologians of the Protestant Reformation, who served for many decades as the chief pastor of Geneva. He wrote commentaries on most books of the Bible, which were reworked from lectures he gave to theological students. He is commemorated on May 26 or May 28 on the liturgical calendars of several Anglican churches.