John Calvin Commentary 1 Timothy 1:19

"holding faith and a good conscience; which some having thrust from them made shipwreck concerning the faith:" — 1 Timothy 1:19 (ASV)

Having faith and a good conscience I understand the word faith to be a general term, denoting sound doctrine. In the same sense he afterwards speaks of the mystery of faith (1 Timothy 3:9). And, indeed, the chief things demanded from a teacher are these two: that he must hold to the pure truth of the gospel, and next, that he must administer it with a good conscience and the holiest zeal. Where these are found, all the others will follow of their own accord.

From which some having turned aside concerning faith He shows how necessary it is for faith to be accompanied by a good conscience, because, conversely, the punishment for a bad conscience is to turn aside from the path of duty. Those who do not serve God with a sincere and a perfect heart, but give a loose rein to wicked dispositions, even though at first they had a sound understanding, eventually lose it altogether.

This passage should be carefully observed. We know that the treasure of sound doctrine is invaluable, and therefore there is nothing we should dread more than having it taken from us. But Paul here informs us that there is only one way of keeping it safe, and that is, to secure it by the locks and bars of a good conscience. This is what we experience every day. For how is it that so many, laying aside the gospel, rush into wicked sects or become involved in monstrous errors? It is because God punishes hypocrisy with this kind of blindness; while, on the other hand, a genuine fear of God gives strength for perseverance.

From this we can learn two lessons.

1. Teachers and ministers of the gospel—and through them, all the churches—are taught with what horror they should regard a hypocritical and deceitful profession of true doctrine, when they learn that it is so severely punished.
2. This passage removes the offense that greatly distresses so many people when they perceive that some, who formerly professed attachment to Christ and to the gospel, not only fall back into their former superstitions but (which is far worse) are bewildered and captivated by monstrous errors.

For by such examples, God openly supports the majesty of the gospel, and openly shows that He cannot at all endure its profanation. And this is what experience has taught us in every age. All the errors that have existed in the Christian Church from the beginning proceeded from this source: ambition in some people, and covetousness in others, extinguished the true fear of God.

A bad conscience is, therefore, the mother of all heresies. We see that a vast number of people, who had not sincerely and honestly embraced the faith, are hurried along like brute beasts into the reveries of the Epicureans, so that their hypocrisy is exposed.

Not only that, but contempt of God is universally prevalent. The licentious and disgraceful lives of people of almost all ranks show that there is either no integrity at all, or the smallest possible portion of it, in the world.

Consequently, there is very great reason to fear that the light which had been kindled may be quickly extinguished, and that God may leave the pure understanding of the gospel to be possessed by very few.

Have made shipwreck: The metaphor taken from shipwreck is highly appropriate.

It suggests to us that if we wish to arrive safely at the harbor, our course must be guided by a good conscience; otherwise, there is danger of “shipwreck”—that is, there is danger that faith may be sunk by a bad conscience, as by a whirlpool in a stormy sea.