John Calvin Commentary 1 Peter 3:15

"but sanctify in your hearts Christ as Lord: [being] ready always to give answer to every man that asketh you a reason concerning the hope that is in you, yet with meekness and fear:" — 1 Peter 3:15 (ASV)

Although this is a new precept, it still depends on what has gone before, for he requires such steadfastness in the faithful, that they boldly give a reason for their faith to their adversaries. And this is a part of that sanctification which he had just mentioned; for we then truly honor God when neither fear nor shame prevents us from making a profession of our faith.

But Peter does not expressly command us to assert and proclaim what has been given to us by the Lord everywhere, always, and among all indiscriminately, for the Lord gives His people the spirit of discretion, so that they may know when, how far, and to whom it is advisable to speak.

He commands them only to be ready to give an answer, lest through their sloth and the cowardly fear of the flesh, by being silent, they expose the doctrine of Christ to the derision of the ungodly. The meaning, then, is that we ought to be prompt in declaring our faith, so as to present it whenever necessary, lest the unbelieving, through our silence, condemn the religion we follow.

But it should be noted that Peter here does not command us to be prepared to solve any question that may be raised, for it is not everyone's duty to speak on every subject. Rather, what is meant is the general doctrine, which pertains even to the unlearned and the simple.

Therefore, Peter intended nothing other than that Christians should make it evident to unbelievers that they truly worshipped God and had a holy and good religion. And in this there is no difficulty, for it would be strange if we could offer nothing to defend our faith when anyone inquired about it. For we ought always to ensure that all may know that we fear God and that we piously and reverently regard His legitimate worship.

This was also required by the circumstances of the times: the Christian name was much hated and considered infamous; many thought the sect wicked and guilty of many sacrileges. It would have been, therefore, the greatest betrayal of God if, when asked, they had neglected to give testimony in favor of their religion. And this, I think, is the meaning of the word apology, which Peter uses; that is, that Christians were to make it evident to the world that they were far removed from all impiety and did not corrupt true religion, on account of which they were suspected by the ignorant.

Hope here is, by metonymy, to be taken for faith. Peter, however, as has been said, does not require them to know how to discuss every article of the faith distinctly and with sophistication, but only to show that their faith in Christ is consistent with genuine piety.

And from this we learn how all those who understand nothing certain about their faith, and have no answer to give for it, abuse the name of Christian. But it is fitting for us to consider carefully again what he says when he speaks of that hope that is in you; for he implies that only the confession that flows from the heart is approved by God. For unless faith dwells within, the tongue chatters in vain. It ought, then, to have its roots within us, so that it may afterward bring forth the fruit of confession.