1 Corinthians 11:27

After the same manner also he took the cup, when he had supped, saying, This cup is the new testament in my blood: this do ye, as oft as ye drink it, in remembrance of me.

For as often as ye eat this bread, and drink this cup, ye do shew the Lord’s death till he come.

But let a man examine himself, and so let him eat of that bread, and drink of that cup.

For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord’s body.