1 Corinthians 11:27-30

27 Therefore whoever eats this bread or drinks the Lord's cup in a manner unworthy of the Lord will be guilty of the body and the blood of the Lord.  28 But let a man examine himself, and so let him eat of the bread, and drink of the cup.  29 For he who eats and drinks in an unworthy manner eats and drinks judgment to himself, if he doesn't discern the Lord's body.  30 For this cause many among you are weak and sickly, and not a few sleep.