1 Corinthians 11:28-31

Young's Literal Translation

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.

³⁰ Because of this, among you many [are] weak and sickly, and sleep do many;

³¹ for if ourselves we were discerning, we would not be being judged,