Suffering is not a palatable thing to contemplate and nobody likes to look forward to it, but it incidentally has become unavoidable in the world and this side of eternity. Biblical accounts of the lives of people of God are full of sufferings. Isaiah described Jesus the son of God as despised and rejected by men, a man of sorrows, and familiar with suffering (Isa 53:3) In the wisdom of God, suffering here on earth has good purposes and we do well as believers to learn about these purposes so that we would not derail from God's plan.
Consequences of Adams' fall
The earth and everything God created was good and filled with bliss. When Adam fell, he incurred the curses of God upon himself and all creation. He lost the capacity to do good. Erstwhile, he was to have dominion over all creation but after the fall, the same animals he named became wild and terror to him. Everything had changed. The earth would not yield its fullness again but produce thorns and thistles. There came new vocabularies: sufferings, pains, disasters, fear, accidents, sickness, weakness, death and all other consequences of sin.
Training in righteousness
However, God did not leave man in this condition, he sent his only son Jesus Christ to atone for the sin of man. In God's unquestionable wisdom, Jesus' work of salvation was to come with a lot of suffering and culminate on the cross. Adam lost a perfect life and it was only the blood of a perfect man that could atone for the sin. This same Jesus warned that if any man would follow him, he must take his cross on daily basis and follow him. He explained further that the servant cannot be higher than his master; if the world hated him definitely they must hate his followers. This is because Satan is still at work to ensure man remain depraved. Once a man gives his life to Christ, he has automatically become devil's enemy, so, all the persecutions, disgrace, tongue-lashing and wicked treatments meted out to Jesus are also attracted to the believer. The flesh and the Spirit are always in antagonism. This brings suffering. It is painful to leave the pleasures and easy life of sin.
Combat training
God is constantly training believers in righteousness and to make them capable to help others. As the believer grows in faith, his training curriculum becomes tougher. As he comes closer to Christ, his temptations become more subtle. To whom more is given more is also expected. God begins to give allow tougher challenges and tests of faith and this means more painful experiences. The reason for this is to make him more capable to fight the battles of faith that he may face in the future. It is like an athlete training for a championship. He may start with short dashes and as his stamina develops, he increases the distance steadily to ensure he becomes fit enough to make it on the day of the competition. Some of the sufferings we are called to endure are allowed so that we may be fit to resist the devil and become more like Jesus.
Consequences of sinful life
Some sufferings may come about as a direct result of past sinful habits. Christians who have indulged in alcohol or tobacco abuse in the past may show tendencies of high blood pressure or kidney failure. These pains may remain with them till death. Again, if one lived an adulterous life before accepting Christ, she may still have to suffer the pains of venereal disease or a broken home even as Christian. Children and relations may suffer as well. This is not God punishing sin yet; it is direct consequence of breaking the instructions of the author of life.
God's oversight function
Then God himself has the right to award some punishments for our sins even here on earth before the last day. These types of punishments are as a result of His need to regulate things here and they are meant to correct. The Psalmist wrote that, the scepter of the wicked will not remain over the land allotted to the righteous, for then the righteous might use their hands to do evil (Psalms 125:4). This punishment might bring some pains to the erring, their relations and close friends. Many times in the Bible, the Israel had to suffer famine and oppression of enemies as direct consequences of apostasy. The books of Judges present good examples of such cases. Where this type of discipline does not result in death, believers are admonished to endure patiently. Hebrews 12:7,8 reads thus: Endure hardship as discipline; God is treating you as sons. For what son is not disciplined by his father? If you are not disciplined (and everyone undergoes discipline), then you are illegitimate children and not true sons.
Unbelief
Unbelief is a terrible sin and it may cause perpetual sufferings for Christians if they continue to exhibit the trait. God's blessings are based on the promises he has made and believers are bound to believe him to be able to appropriate any of these blessings. Many people live with the minimal grace and continue to suffer in the midst of abundance because of their unbelief. Let anyone who doubts think he could get anything from God. Unbelief is exhibited in various forms like fear, self pity, defeatist attitude, ignorance of the word of God, reluctance to suffer, laziness to pray, greed and stinginess to mention a few.
Enemy action to cause to sin
There is a song composed by Isaac Smith which I like to sing every morning as I step out of my house. The second stanza goes thus:
The world, the flesh, and Satan dwell
Around the path I tread;
O, save me from the snares of hell,
Thou Quickener of the dead.
To be is to be related. The world out there is full of depraved human beings who have lost the capacity to know what is good, much less aspiring to do it. We may be recipients of some of their evil activities. A bus driver who refuses to observe traffic laws can maim or kill a young student returning from school. Satan is also there, whom Peter described as a roaring lion seeking whom to devour. God is in control quite alright and he may just allow some of this to affect even his children. He knows why and we know that his actions are always good. I am always consoled by one passage in the Prophecy of Isaiah, which reads thus: Therighteous perish, and no one ponders it in his heart; devout men are taken away, and no one understands that the righteous are taken away to be spared from evil (Isa 57:1)
Persecutions
The fact that you have become a follower of Christ and are doing his will makes you a special target of the devil. Surprisingly, the tool most likely to be used against you is the religious order of the day. Jesus faced it as the Jews vehemently opposed his claim. The apostles faced it and so were the reformers. Persecutions are major sources of suffering for Christians.
Whichever way suffering comes, let's be encouraged that Christ sees all tears and undergoes all pains with his true followers. Of suffering as a necessary part of a believers life, Peter wrote that to this you were called, because Christ suffered for you, leaving you an example that you follow in his footsteps (1Pet 2:21).