John Wesley on 1 Timothy 1:19

Holding fast faith - Which is as a most precious liquor. And a good conscience - Which is as a clean glass. Which - Namely, a good conscience. Some having thrust away - It goes away unwillingly it always says, "Do not hurt me." And they who retain this do not make shipwreck of their faith. Indeed, none can make shipwreck of faith who never had it. These, therefore, were once true believers: yet they fell not only foully, but finally; for ships once wrecked cannot be afterwards saved.