1 Corinthians 11:31,32

'But if we discerned ourselves, we should not be judged (krino). But when we are judged (krino), we are chastened of the Lord, that we may not be condemned (katakrino) with the world.'

These things (the sickliness and the deaths) arise, he points out, because they are not discerning about their own state, they do not recognise themselves as not behaving like the true body of Christ (they do not discern the body). They arise from God's chastening of them as a result of His judgment on them, which, had they been spiritually discerning they would have avoided. Yet nevertheless they can console themselves in this, that His chastening is in order to prevent the necessity of His final judgment (katakrino) on them, the final judgment that is coming on the whole world. Let them take heed to His chastening, therefore, and repent.

So three ideas are prominent. The first is the need for us to discern 'ourselves' (doubly stressed), that is by self-examination and coming to the light of the Lord to examine ourselves and seek His forgiveness and renewal (compare 1 John 1:7). The second is that should we fail to discern ourselves God will do it for us and enter into judgment with us and chasten us. And the third is that, while He deals with us as His own by chastening, even severe chastening, the world outside awaits final severer judgment.