1 Corinthians 11:27-29

Young's Literal Translation

²⁷ so that whoever may eat this bread or may drink the cup of the Lord unworthily, guilty he shall be of the body and blood of the Lord:

²⁸ and let a man be proving himself, and so of the bread let him eat, and of the cup let him drink;

²⁹ for he who is eating and drinking unworthily, judgment to himself he doth eat and drink -- not discerning the body of the Lord.