Many years ago, I read and summarised John Wenham’s thoughts on this subject.  I reproduce my notes here.

1. It is good that we are free agents, not machines.  This freedom to accept or reject seems essential to a living, loving relationship with God, but comes with it the possibility of sin in all its horror.

2. It is good that sn is linked with suffering as a deterrant.  It may well be true that all suffering is a result of sin (Gen 3:14-19).  In a world without sin, even if illness, old age and accident remained, there would be unselfishness, neighbourliness, gratefulness and courage, instead oa war, greed, lust and fear.  It is well known that many illnesses are caused or exaccerbated by unhappiness and other mental conditions.

Just as pain in everyday life serves as an invaluable deterrant (e.g. withdrawing fingers from a hot flame) and may even intensify pleasure (a refreshing drink after intense thirst), suffering serves as God’s warning of the consequences – temporary and eternal- of sin (think of the miseries produced by excessive drinking, adultery, laziness and greed).

3. It is good that sin is linked with suffering in retribution.  Retribution is not revenge: it is punishment according to desert of a responsible person.  There are three elements to punishment: deterrance, reformation and retribution.  Many would recognise only the first two.  Yet deterrance divorced from retribution can be a terrible weapon of injustice.  It is only on the basis that a crime has a just desert that we can have any concept of over-punishment or punishment of the innocent on exemplary grounds.

Likewise, reformation divorced from retribution is sinister: this stems from calling crime a ‘disease’ and replacing punishment with a ‘cure’.  But:

• the cure would be just as compulsory as what used to be called ‘punishment’;
• the ‘cure’ can extend to any measure which is successful, and may be far beyond what is demanded by justice;
• if crime is a ‘disease’ to be ‘treated’ compulsarily, then any state of mind which our masters choose to call ‘disease’ can be ‘treated’ in the same way.  Religion could be called a ‘neurosis’ and Christians would vanish into Institutions for the Treatment of the Ideologically Unsound.

We repeatedly observe that children thrive in an environment where rules are kept and where punishments are generally administered swiftly and fairly.

Against this solid background of justice the concept of mercy is best seen.  God has revealed that the just desert of sin is perdtion (Rom 6:23), and compared with this the judgments of the Bible and present-day horrors are small.  God is continually offering, and granting, mercies to us which are all undeserved.  And any apparent unfairness on God’s treatment of us arises, not because some have too much punishment, but because some appear to have too little.  None of us will ever receive harsher punishment than we deserve.

4. It is good that retribution (and rewards), though certain, are often delayed.  The sudden judgments on Uzzah, Herod Agrippa, Ananias and Sapphira, Gehazi and Uzziah, are exceptional – reminders of the reality of God’s judgments.  Examples of a particular disease following a particular sin (say, STD), are unusual.  God gives time for repentance, deepening faith, and purifying motives.  See Jn 9:1-3; Lk 13:4f; Gen 15:15; Lk 13:34; 2 Pet 3:9.

5. It is good that the results of sin (and of goodness) are not confined to the doer.  Life would be unthinkable without the corporate principle, and it is rgith that we should be treated corporately responsible, as well as individually accountable.

6. It is good that suffering is limited in degree and in time.  It is probable that no-one has suffered as much as Christ did, but he was able to take a long view (Heb 12:2; see also Jn 16:21; 2 Cor 4:17).  In regaining the eternal perspective, our sense of values and priorities will begin to be restored (Mt 10:28; cf. Psa 73; Hab).

7. It is good that suffering can promote spiritual life.  It is paradoxical, but true, that though a mature Christian is committed to  a struggle to relieve the suffering of others, he accepts it for himself, James 1:2-4.

As a theory, this view seems harsh, but in practice, suffering:

• is part and parcel of the way of the cross (Heb 12:2), and persecution is a way to blessing, Mt 5:10;
• leads to resilience and comradeship.  It teaches sympathy and purity.
• brings sin to the surface, where it can more readily be dealt with, Heb 12:6;
• keeps us dissatisfied with the world, and yearning for our true home;
• is an almost invariable accompaniment of life’s richest and most worthwhile experiences (as in sports, exploration, childbirth, art);
• prompts the Christian to trust wholly in God’s love and care;
• is frequently the instrument of a sinner seeking Christ for salvation.

8. Our supreme good has come through suffering.  Our faith was born in Christ’s suffering; therefore, suffering need not destroy faith.  We should not gasp at God’s permitting suffering when we see the agony entailed in his decisive overthrow of evil.

9. It is significant that the One who lived in the closest communion with God was not shocked by the severity of divine judgments.  Our Lord spoke of their reality – both past and future.  And this was the loving and compassionate Saviour!

10. When all else has been said, we cannot expect fully to understand God’s ways (Rom 11:33-36).  But what he has revealed of himself makes us sure of both his goodness and his severity (Rom 11:22), and urges us to take note and to take heed.

Condensed from The Goodness of God, pp50-88.  See also the second edition of that book, published as The Enigma of Evil, pp36-100.