A major theme in Peter's first epistle is suffering. FL Cross said,
The Greek verb 'suffer' occurs twelve times in the epistle, as opposed to sixteen times in the rest of the New Testament epistles. Similarly, the noun "suffering" is used four times in Peter, and only ten times in the other New Testament epistles. 
Peter has used the word 'suffer', in relation to the sufferings of Christ and those that Christians have to bear as a sort of Ariadne thread for the whole work".
Peter is immensely interested in the nature of suffering. It should be noted though, that he is not here interested in general human suffering. His central concern is with those who suffer for the cause of God. They suffer for their loyalty to God.
Peter addresses himself to those who suffer as Christians. The starting point for Peter is the suffering of Christ. Although Jesus was innocent, he suffered a cruel death on the cross.
The prophets of the Old Testament, moved by the Spirit, predicted his sufferings (1 Pet 1:10, 11).
Peter, more than any other New Testament writer, links Jesus with the suffering servant of Isaiah (1 Pet 2:22-25). Suffering is the consequence and the only cure for sin. It must be faced, if God is to intervene in the world to save men. Suffering had to be borne by the righteous for the unrighteous (1 Pet 3:18). Jesus bore our sins in his body on the cross that we might be freed from our sin (1 Pet 2:14).
God loved the lost world, and wanted to redeem it, so Jesus had to suffer humiliation and the agony of cross. He is the Passover lamb, who shed innocent and precious blood (1 Pet 1:19). For Peter the sufferings of Jesus are the basis of an understanding of human suffering. He elaborates a number of implications for Christians who suffer.
Suffering is NormalThe first implication of Christ's suffering is that those who follow him will also suffer. This may come as a surprise to those who think that Jesus came to rescue us. They think that his sufferings will relieve our suffering. Many Christians believe that Jesus suffered for us, so that we will not have to suffer.
This is not the view of Peter. The hard message of his epistle is that since Christ suffered, his followers should also suffer. Jesus was sinless and yet he was hated and mistreated. Those who follow him cannot expect exemption from similar treatment 
To be a Christian is to follow Christ. Anyone who follows in his footsteps and lives the same kind of life is also bound to suffer.
To this you have been called, because Christ also suffered for you, leaving you an example, that you should follow in his steps (1 Pet 2:21).Suffering is not just a vague possibility, but something which Christians should be ready to meet.
Therefore, we should not he surprised when suffering comes upon us.
Dear friends, do not be surprised at the painful trial you are suffering, as though something strange were happening to you (1 Pet 4:12).Jesus made this very clear to the disciples. He repeatedly warned that discipleship involves suffering. Everyone who would follow him must take up the cross (Mk 2:34). He promised them that they must drink the same cup of suffering as he drank, and be baptised with the same baptism of fire (Mk 10:35-45).
Jesus' gospel did not promise a soft cosy life, but was a call to a life of hardship, suffering and humiliation, just like his own. So when suffering comes, we should not be surprised.
Consequence of ObedienceAn authentic Christian lifestyle should produce suffering. Peter identifies the Christian life with a life of love that does not return evil for evil, but meets wrong with right , abuse with blessing, and unjust power with suffering (1 Pet 2:22, 3:8,9). Peter expects that any Christian who lives in this spirit will receive suffering, because they are alienated from those who hold power in the world.  A lifestyle of unconditional love in a sinful and hard world, can only lead to suffering.
Yet this is the life to which we are called. In a hostile world, steadfast loyalty to Christ will lead to trials and trouble. Life is a battleground where the forces of good and evil meet, so those who take Christ's side must expect to be attacked by the forces of evil. Our struggle is against the devil, so a life of love, makes us vulnerable to his attack . For Peter, suffering is an inevitable consequence of a godly life.
God's WillThe fact that Jesus suffered implies that, suffering is God's will for those whom he loves (1 Pet 3:17; 4:19). It may be inflicted by a pagan people, and even be the work of the devil, but it is still part of the divine purpose and plan. This is not easy to accept, but the reason has been well expressed by John Ferguson. In God's mysterious providence suffering is a fact of life in the world, which is incomplete because it is not given over in full obedience to God as king.
The love of God reaches out to heal such suffering. God's way is not to meet violence and sin with violence and sin, but with suffering and love. God brings in his kingdom, not as a conquering: commander, but as the suffering servant.
He turns alienation to atonement by suffering. Sin seeks to conquer love by inflicting suffering; love conquers sin by accenting the suffering . Christians are part of the divine plan for the redemption of the world. As part of that plan, we can expect suffering as part of God's will for us. This suggests that those of us who are living in comfort in the West may have missed part of that plan.
Pathway to GloryAn important aspect of Jesus sufferings is that they were the pathway to his glory. Peter continually links the suffering of Jesus with his glory (1 Pet 1:11; 1:21; 4:13; 5:1).
The prophets who foretold his suffering, also foretold his glory (1 Pet 1:11). After Jesus suffered by "being put to death in the flesh", he was raised into heaven, "and is at the right hand of God, with angels, authorities, and powers subject to him" (1 Pet 3:18, 22). He received his glory through suffering. Just like Jesus, we also will receive glory through suffering. Peter says,
If you are reproached for the name of Christ, you are blessed because the Spirit of glory and of God rests upon you (1 Pet 4:14).This amazing promise suggests that most glory seekers are looking in the wrong place. Those who partake in Christ's sufferings are the ones who share in his glory. This glory will be fully revealed in the future, but is partly upon them now. Suffering and glory cannot be separated.
JH Burtness says,
It is a fundamental fact of New Testament faith that resurrection comes only after death, that Easter comes after Good Friday, that renewal comes only through suffering.Christians cannot bypass the cross. Only when we are united with Christ in his sufferings, can we share with him in the fullness of his glory.
The church has perhaps not so often been true to itself and to its Lord. But at those times and at those places where it has followed him, it has also shared in his suffering, and in that suffering it has discovered the joy of renewal. 
Rejoice in sufferingChrist's suffering gives those who suffer a reason to rejoice. They are sharing in the glory of Jesus, so Peter urges them to rejoice.
But rejoice that you participate in the sufferings of Christ, so that you may be overjoyed when his glory is revealed. (1 Pet 4:13).Peter commends the Asian Christians for rejoicing in their troubles (1 Pet 1:6) For him, it is a great privilege to be a Christian. They have been "born anew" (1 Pet 1:7) and have been given a great new life that is "guarded through faith" (1 Pet 1:5)
Praise be to the God and Father of our Lord Jesus Christ! In his great mercy he has given us new birth into a living hope through the resurrection of Jesus Christ from the dead, and into an inheritance that can never perish, spoil or fade-kept in heaven for you,(1 Pet 1:3,4). We have this wonderful privilege, so we can rejoice even in suffering. We are chosen by God, and nothing can take away the joy that this knowledge brings.
Even suffering is a cause for rejoicing because it purges and strengthens our character, unites us with Christ, and is a prelude to the glorious recompense of the last day . God's love and power is a guarantee of our hope, so we can rejoice with confidence.
Redemption through SufferingAnother important aspect of Christ s suffering is its redemptive effect. Our suffering as Christians helps sanctify us, because God is leading us towards a Christ-like life through our suffering. Peter makes this clear in 1 Peter 4:1,
Arm yourselves also with the same attitude, because he who has suffered in his body is done with sin.God is a holy God, and we are to be holy like him. God makes us holy through suffering.
And the God of all grace, who called you to his eternal glory in Christ, after you have suffered a little while, will himself restore you and make you strong, firm and steadfast(1 Pet 5:10).God used their troubles to make them pure like refined gold, which has been tested by the refiners fire (1 Pet 1:7).
In this you greatly rejoice, though now for a little while you may have had to suffer grief in all kinds of trials. These have come so that your faith-of greater worth than gold, which perishes even though refined by fire-may be proved genuine and may result in praise, glory and honour when Jesus Christ is revealed (1 Pet 1:6,7).God allowed sufferings to test and refine our faith, so that our lives may bring praise and glory to him. Suffering breaks the bonds that hold men of sin and futility, with all its consequences.
Suffering for Doing EvilSuffering leads to holiness, but not all suffering has this redemptive quality. Peter warns that Christians must only suffer according to God's will.
But let none of you suffer as a murderer, a thief, an evildoer, or as a busybody in other people's matters. (1 Pet 4:15).In these circumstances, suffering is what we deserve. 
Peter reminds Christians that they should only suffer for doing good.
But how is it to your credit if you receive a beating for doing wrong and endure it? (1 Pet 2:20).
It is better, if it is God's will, to suffer for doing good than for doing evil (1 Pet 3:17).The suffering to which we are called is suffering as Christians. We should be perfect in our behaviour, so there is no just cause for complaint against us (1 Pet 3:15, 16).
Self-inflicted sufferingSelf-inflicted suffering has no value. Christians can become obsessed with suffering, and seek opportunities to suffer. Some even beat their own bodies. This is wrong, because suffering in itself is not virtuous. Only if it is used to glorify God does it have value. Thomas Merton says that although prayer and sacrifice require each other, premature martyrdom is only inverted egotism.
It would be more sincere and more religious to eat a full dinner in the spirit of gratitude, than to make a sacrifice of part of it with the feeling that one is suffering martyrdom. Self chosen sacrifices are nearly always inferior to those unasked for ones which the situation throws in the way. 
Respond with LoveIf suffering is God's will we must respond to it in God's way. Therefore, Peter outlines the response a Christian should give to persecution and rough treatment. It is not an easy response. A Christian must not respond to opposition or hostility with hate or retaliation, but with love . This should be evident from the example of Christ.
When they hurled their insults at him, he did not retaliate; when he suffered, he made no threats. Instead, he entrusted himself to him who judges justly (1 Pet 2:23).Christians should follow his example.
Do not repay evil with evil or insult with insult, but with blessing, because to this you were called so that you may inherit a blessing (1 Pet 3:9).If Christians retaliate, the wrongdoer will be put off the Christian life. Retaliation leads to bitterness, so the best response to evil is love.
SubmissionChristians should also respond to suffering in a spirit of submission. An important theme in the epistle is submission to authority, even where it is heathen and harsh. Selwyn says that the trait of Jesus' character which was most admired by Peter was his meekness. He laid aside his divine glory and followed this humiliation though, even to the Cross, He is the one who suffered and did not threaten, though he had the power to do so.
Christians must follow this example and react to all authority with humility and submission. God will oppose those who are proud and give grace and protection to those who are humble. We do not submit blindly to authority, but freely for the sake of the gospel.
Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day he visits us.
Submit yourselves for the Lord's sake to every authority instituted among men: whether to the king, as the supreme authority, or to governors.... For it is God's will that by doing good you should silence the ignorant talk of foolish men (1 Pet 2:12-15Peter admits that the authority of rulers and governors comes from man, but he urges submission to them so that the gospel will not be hindered. The political leaders might be the enemies of God, but we are required to respond to our enemies with love. For Peter love involved submission.
Good WorksChristians should respond to suffering with good works. Peter does not call for passive resignation to suffering, but demands a demonstration of love towards our enemies through active kindness. Over and over again Peter urges the Christians to do good works (1 Pet 1:15; 2: 12, 13; 3:6, 11, 13, 17; 4 19).
He is not suggesting that salvation is by works, but rather he is concerned that persecution may cause Christians to withdraw from their society. Instead of retreating, we should actively attack evil by doing good whenever we can.
Suffering should not diminish our zeal for performing acts of love, but spur us on. If Christians who are persecuted respond in these ways, they will bring glory to God through their suffering. They should refrain from retaliation and commit their cause to God.
ComfortAlthough Peter sees suffering as part of God s will for Christians, he does not diminish its seriousness. Rather he calls it a fiery ordeal (1 Pet 1:12). He does not pretend that the Christian life is easy, but declares that it will be hard. This is demonstrated by the urgency with which he encouraged the people receiving his letter.
By pointing out the glory which is theirs, and the benefits which their suffering will bring, he hopes to comfort them. Peter has suffered, so he knows how hard suffering can be. He urges the Christians not to lose heart, or be overcome by their difficulties.
If we hold fast, then the God who has called us will bless us, and bring us into his glory. In our suffering we are sharing with Christ, and this is the greatest privilege that anyone can have. So even in the hardest times we can rejoice.
Then we will be able to share with him in all his glory, when it is eventually revealed. This is a glorious message for us, should we ever be called to suffer for the name of Jesus.
And the God of all grace, who called you to his eternal glory in Christ, after you have suffered a little while, will himself restore you and make you strong, firm and steadfast (1 Pet 5:10).
 FL Cross, 1 Peter: a Paschal Liturgy, p. 14.
 FL Cross, 1 Peter: a Paschal Liturgy, p. 13.
 M Stibbs & AF Walls, The First Epistle General of Peter, p189.
J Ferguson, The Place of Suffering, p.5.
FV Filson, Partakers with Christ, p.401.
 J. Ferguson, The Place of Suffering, p.87.
 EG Selwyn, The First Epistle of Peter, 91.
 FG Selwyn, The First Epistle of Peter, p.79.
 J Ferguson , The Place of Suffering, p. 92.
 T Merton, The Contemplative Life, p.22
 FV Filson, Partakers with Christ, p. 406.
 EG Selwyn, The First Epistle of Peter, p.91.