1 Corinthians 11:26-28

11:26 For every time you eat this bread and drink the cup, you proclaim the Lord’s death until he comes.

11:27 For this reason, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of the body and blood of the Lord. 11:28 A person should examine himself first, and in this way let him eat the bread and drink of the cup.