1 Peter 4:13

but insomuch as ye are partakers of Christ's sufferings, rejoice; that at the revelation of his glory also ye may rejoice with exceeding joy.

Partakers of Christ's sufferings ... How is the Christian's suffering a sharing in the sufferings of Christ? First, their sufferings are caused by the same thing. Christ died for testifying under oath that he is the divine Son of God, and the Christians of Peter's day who were confessing the same eternal truth were due shortly to suffer even as Christ suffered. Over and beyond this is the identity of the church as Christ's spiritual body, making the church's sufferings to be those of Christ himself.

At the revelation of his glory ... Peter used this same expression in 1 Peter 1:7; and, in both places, it is better to understand it as a reference to the Second Advent, the general resurrection and judgment of the last day, and the visible revelation of Christ before all people as the Redeemer and Judge. Such a revelation is that mentioned by Paul in 2 Thessalonians 1:7-10.