Is human suffering related to sin? The answer is yes, but the relationship is often perceived incorrectly.
That suffering and sin are related is beyond refute. We need only recall the familiar "curse" passage from Genesis.
It is also true that entire populations, such the inhabitants of Sodom and Gomorrah, have suffered as a direct consequence of their sins.
What is wrong, however, is take this truth to an unsupported conclusion, namely that all or most human suffering is in proportion to our sinfulness. In spite of a lack of support in scripture, this is a recurring theme: that sickness, natural disasters, terrorist attacks, and (as a less common but more pathological example) a lack of prosperity are related to sinfulness.
The book of Job should be sufficient to put this falsehood to rest. Job suffers, perhaps as no mere man has ever suffered, and yet he was "blameless and upright." Just in case anyone misses the point, Job's friends make that argument, that Job's sin is behind his suffering, but their theology is found wanting.
Furthermore, in any number of passages (let alone in real life) we see clear evidence that the wicked, far from suffering, actually prosper.
Jesus also teaches this truth, that we should not correlate human suffering with the degree of sinfulness of the inflicted. Recall his encounter with a man blind from birth:
1As he passed by, he saw a man blind from birth. 2 And his disciples asked him, “Rabbi, who sinned, this man or his parents, that he was born blind?” 3 Jesus answered, “It was not that this man sinned, or his parents, but that the works of God might be displayed in him. (John 9:1-3)His disciples were not trying to trick Jesus. But they did demonstrate this same, common misconception about a connection between sin and suffering by phrasing their question in the form of a false dilemma, asking Jesus as if there were but two possible answers: either the sin of this man or the sin of his parents led to his blindness. Jesus avoids the false dilemma by answering: neither.
This may or may not be a comforting truth, that our suffering is not correlated with our sin. Jesus teaches elsewhere on this matter, in a way that is decidedly uncomfortable. In the thirteenth chapter of Luke we read:
1 There were some present at that very time who told him about the Galileans whose blood Pilate had mingled with their sacrifices. 2 And he answered them, “Do you think that these Galileans were worse sinners than all the other Galileans, because they suffered in this way? 3 No, I tell you; but unless you repent, you will all likewise perish. 4 Or those eighteen on whom the tower in Siloam fell and killed them: do you think that they were worse offenders than all the others who lived in Jerusalem? 5 No, I tell you; but unless you repent, you will all likewise perish.” (Luke 13:1-5)Here the teaching is not about sickness or blindness, but about unfathomable crimes and inexplicable accidents that befell innocent people. Representing the former, we have the story of worshippers who were murdered by Pilate's soldiers-not during an act of protest or other civil unrest but while they were at a synagogue. And in the latter case we have eighteen bystanders crushed in the collapse of a tower.
Here Jesus is being asked: "why do bad things happen to good people?" His answer (to both calamities) is fairly astonishing: do you think they are worse sinners than you? Well they were not. And unless you repent, you will likewise perish. This response is, in many ways, brutal. He says, in effect, the right question is not why did bad things happen to the worshipers in Galilee or the pedestrians in Siloam, but why don't bad things happen to you? You deserve it as much if not more that those about whose plight you inquire.
Jesus' answer is a reminder that we all are in rebellion against a Holy God, and that every breath we take is a punishment postponed, and for the impenitent it will be a punishment not delayed indefinitely. For those who do repent, we are saved and spared by God's grace—nothing more, nothing less. In this world we may and will suffer, but in the next there will be no towers of Siloam.