Affliction, however, has to do with pain or difficulty that is threatening-suffering in which no good outcome can be predicted. Notice the illustration Paul uses in verse 5 when he speaks of the sufferings and comfort of Christ overflowing into our lives. It is as if the apostle is picturing a stream of flowing water in which we are all participants, not a cistern or a well in which we are isolated from one another. Comfort comes from the God who is comfort himself. It is offered to a believer who learns this lesson and in turn is able to offer comfort to another.
Sin is an isolater.
It makes us withdraw from others so that we don't ask for help because we are too proud, or we don't offer help because we are too selfish. But when the affliction becomes too hard to bear, then we find ourselves entering into the lives of one another. In that way, suffering can be regarded as one of the building blocks to community, as we see God giving life where suffering was present. Paul is counting on this. Remember that he and the Corinthians did not get along very well.