27 aWhoever, therefore, eats the bread or drinks the cup of the Lord bin an unworthy manner will be guilty concerning cthe body and blood of the Lord. 28 dLet a person examine himself, then, and so eat of the bread and drink of the cup. 29 For anyone who eats and drinks without discerning the body eats and drinks judgment on himself.
1 Corinthians 10:16
1 Corinthians 11:27–29