1 Peter 1:6

The first word, wherein, refers to the apostle's foregoing discourse about the excellency of their present state, and their grand expectations for the future. "In this condition you greatly rejoice, though now for a season, or a little while, if need be, you are made sorrowful through manifold temptations," Pe1 1:6. I. The apostle grants they were in great affliction, and propounds several things in mitigation of their sorrows. 1. Every sound Christian has always something wherein he may greatly rejoice. Great rejoicing contains more than an inward placid serenity of mind or sensation of comfort; it will show itself in the countenance and conduct, but especially in praise and gratitude. 2. The chief joy of a good Christian arises from things spiritual and heavenly, from his relation to God and to heaven. In these every sound Christian greatly rejoices; his joy arises from his treasure, which consists of matters of great value, and the title to them is sure. 3. The best Christians, those who have reason greatly to rejoice, may yet be in great heaviness through manifold temptations. All sorts of adversities are temptations, or trials of faith, patience, and constancy. These seldom go singly, but are manifold, and come from different quarters, the effect of all which is great heaviness. As men, we are subject to sorrows, personal and domestic.

— Matthew Henry's Concise Commentary (public domain)

Wherein--in which prospect of final salvation. greatly rejoice--"exult with joy": "are exuberantly glad." Salvation is realized by faith (Pe1 1:9) as a thing so actually present as to cause exulting joy in spite of existing afflictions. for a season--Greek, "for a little time." if need be--"if it be God's will that it should be so" [ALFORD], for not all believers are afflicted. One need not invite or lay a cross on himself, but only "take up" the cross which God imposes ("his cross"); Ti2 3:12 is not to be pressed too far. Not every believer, nor every sinner, is tried with afflictions [THEOPHYLACT]. Some falsely think that notwithstanding our forgiveness in Christ, a kind of atonement, or expiation by suffering, is needed. ye are in heaviness--Greek, "ye were grieved." The "grieved" is regarded as past, the "exulting joy" present. Because the realized joy of the coming salvation makes the present grief seem as a thing of the past. At the first shock of affliction ye were grieved, but now by anticipation ye rejoice, regarding the present grief as past. through--Greek, "IN": the element in which the grief has place. manifold--many and of various kinds (Pe1 4:12-13). temptations--"trials" testing your faith.

— Jamieson-Fausset-Brown Commentary (public domain)