John Calvin Commentary 1 Peter 3:17

"For it is better, if the will of God should so will, that ye suffer for well-doing than for evil-doing." — 1 Peter 3:17 (ASV)

For it is better belongs not only to what follows but to the entire context. He had spoken of the profession of faith, which at that time involved great danger; he now says that it is much better, if they suffered any loss in defending a good cause, to suffer unjustly than to be punished for their evil deeds.

This consolation is understood more through quiet meditation than by many words. It is a concept indeed found everywhere among secular authors that a good conscience provides a sufficient defense, whatever evils may happen and must be endured. These authors have spoken courageously, but the only truly bold man is he who looks to God.

Therefore, Peter added this clause, If the will of God be so. For in these words he reminds us that if we suffer unjustly, it is not by chance but according to the divine will; and he assumes that God wills or appoints nothing except for the best reason. Consequently, the faithful always have this comfort in their sufferings: they know that they have God as their witness, and they also know that they are led by Him to the struggle, so that under His protection they may give proof of their faith.