1 Corinthians 11:26-29

For whenever you eat this bread and drink this cup, you proclaim the Lord’s death until he comes. So then, 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. Everyone ought to examine themselves before they eat of the bread and drink from the cup. For those who eat and drink without discerning the body of Christ eat and drink judgment on themselves.