First Peter is a letter about living in expectation for the return of Christ from heaven. From beginning to end, the book is saturated with hope. The profound thing is that the hope in which Peter calls Christians to live terminates beyond this evil age. What worldly hope could Peter offer to slaves with cruel masters (1 Peter 2:18-25)? Instead, Peter offers the same hope to them that we have as we struggle in our pilgrimage towards heaven. He called them to set their hope fully on the grace that would be brought to them when Christ would be revealed from heaven (1 Peter 1:13).
John Robbins has written this about First Peter: "Peter did not encourage the persecuted Christians by speaking of the political ascendancy of the church or of Christians; he did not encourage them by speaking of a triumphant institution or movement. He failed to mention Constantine; he ignored the millennium. To encourage the poor Christians Peter spoke only of their irrevocable election to salvation, of the 'inheritance incorruptible and undefiled, that does not fade away, reserved in heaven for you who are kept by the power of God for salvation ready to be revealed in the last time.'" It is this "ready-to-be-revealed salvation" that is the cause of rejoicing for believers on their pilgrimage to heaven.
What encouragement did Peter give to the slaves with cruel masters? Simply this—that it was commendable in God’s sight to suffer injustice (1 Peter 2:19). In this, they were were receiving the highest honor of the Christian life—emulation of Christ (1 Peter 2:21; c.f. Acts 5:41). The encouragement was that after they had suffered a little while, the God of all grace would himself "perfect, establish, strengthen, and settle" them in heavenly glory (1 Peter 5:11). The encouragement was that they had been born again to a living hope of a heavenly inheritance (1 Peter 1:3-4).
What encourages persecuted Christians today? It is the great reward they have in heaven with Christ (Matthew 5:11-12). What encourages imprisoned Christians? It is receiving the crown of life (Revelation 2:10). What encourages pillaged Christians? It is knowing that they "have a better and an enduring possession for [themselves] in heaven" (Hebrews 10:34). What encourages Christians when they are about to die for their faith? It is the sure confidence that in Christ they will not be hurt by the second death (Revelation 2:11).
It is this recurring biblical refrain of heavenly hope that seems to be missing in so many of our eschatological discussions today. The true manna of hope that God gives for our pilgrimage in the world (the hope of glory) is sometimes pushed into the periphery for more (seemingly) pertinent issues like a culture war or political activation. But didn't Paul warn Timothy against this? "You therefore must endure hardship as a good soldier of Jesus Christ. No one engaged in warfare entangles himself with the affairs of this life, that he may please him who enlisted him as a soldier. And also if anyone competes in athletics, he is not crowned unless he competes according to the rules. The hardworking farmer must be first to partake of the crops. Consider what I say, and may the Lord give you understanding in all things" (2 Timothy 2:3-7). Timothy was not to be distracted from his task by other things. He was to, "Remember Jesus Christ, raised from the dead, descended from David" (2 Timothy 2:8). This was the gospel for which Paul was suffering, in order that the elect might obtain salvation in Christ with eternal glory (2 Timothy 2:10). Eternal glory was the focus of the future, even for the cruelly treated slaves to whom Peter was writing.
The Christian should not set his hope on this age made better, even if that is the thing constantly vying for his or her attention from external (and even Christian) sources. Where is heaven in all of this? Who can make straight what God has made crooked (Ecclesiastes 7:13)? Instead, the Christian should set his hope on the age to come, where everything wrong will be made right. "According to [God's] promise," Peter says, "we look [with confident hope] for a new heavens and a new earth in which righteousness dwells" (2 Peter 3:13). If "the end of all things is [indeed] at hand" (1 Peter 4:7), does this heavenly hope saturate us like it did the slaves to whom Peter was writing? Or is our attention constantly drawn away to bettering our cultural situation?