1 Corinthians 11:27-30 NIV

27 Therefore, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord.1

References for 1 Corinthians 11:27

28 A man ought to examine himself2 before he eats of the bread and drinks of the cup.

References for 1 Corinthians 11:28

29 For anyone who eats and drinks without recognizing the body of the Lord eats and drinks judgment on himself.
30 That is why many among you are weak and sick, and a number of you have fallen asleep.3

References for 1 Corinthians 11:30