1 Corinthians 11:31

For if we would judge ourselves, we should not be judged.

If people would judge themselves, they would not be judged, and in the setting of communion this means that each person is to examine himself and partake worthily rather than eat and drink without discerning the Lord's body. Judging the self means honestly examining one's own heart and recognizing one's own faults and sins. It means judging one's own sins rather than hiding them or excusing them.

This self-examination tests whether a person is in the faith. The verse calls people to judge themselves rather than condemn or judge others. It forbids condemning others, whose motives cannot be discerned. It forbids judging another person's conscience and picking at supposed faults.

Honest self-judgment brings self-humiliation, whereas judging others instead is more comfortable for an unsanctified heart. Judging others instead of the self exposes the critic as sharing in the accuser's work. Self-condemnation is followed by faith in Christ, whose blood cleanses sin and makes the sinner fit for heaven.