How does Peter instruct Christians to prepare for impending judgment and endure the fiery trial of persecution?

Because Christ underwent suffering in His physical body, believers must arm their minds with that same resolve, recognizing that he who has suffered in the flesh has ceased from sins. The remaining span of earthly life must no longer be governed by worldly passions, but consecrated wholly to the divine will of God. More than enough time was squandered in former days pursuing the vices of the Gentiles, when people indulged in debauchery, carnal desires, excessive drinking, riotous parties, drinking bouts, and lawless idolatry. Former associates find it baffling that Christians refuse to rush with them into that same deluge of moral dissipation, responding with malicious slander; yet those accusers must render an account before Him who is prepared to judge both the living and the dead. For this reason the gospel was announced even to the dead, so that though judged according to mortal criteria in the flesh, they might live eternally in the spirit according to God.

Recognizing that the culmination of all history is at hand, Christians must exercise sober discretion and remain watchful in prayer. Above all else, they must preserve intense, unwavering charity among themselves, because fervent love covers a multitude of sins. They are to practice mutual hospitality gladly without complaining or reluctance. As each person has received a particular spiritual gift, they must deploy it in service to one another as faithful stewards of the diverse grace of God. Whoever speaks should communicate as delivering the very words of God, and whoever ministers should serve through the energy that God provides, so that in all things God may receive glory through Jesus Christ, to whom belong eternal majesty and dominion.

Peter commands the faithful not to be bewildered by the fiery crucible of affliction testing them, as though some strange misfortune had arrived. On the contrary, they should rejoice in sharing the afflictions of Christ, so that when His glory is revealed they may be filled with exultant joy. If believers are insulted for the name of Christ, they are blessed, because the Spirit of divine glory and power rests upon them. Let no one suffer deservedly as a murderer, thief, slanderer, or coveter of other men’s things; but if anyone suffers for being a Christian, let him feel no shame, but glorify God under that honored name. The decisive time has come for judgment to commence at the household of God; and if it begins first with believers, what will be the fate of those who reject the gospel? If the righteous man is scarcely saved—which Challoner clarifies as meaning only through strenuous effort, vigilant labor, and constant resistance against worldly snares, demonic malice, and fallen human frailty—where will the ungodly and the sinner appear? Consequently, those who endure hardship according to the will of God must entrust their souls in steadfast goodness to their faithful Creator.