1 Corinthians 11:27-30

So anyone who eats this bread or drinks this cup of the Lord unworthily is guilty of sinning against the body and blood of the Lord. That is why you should examine yourself before eating the bread and drinking the cup. For if you eat the bread or drink the cup without honoring the body of Christ, you are eating and drinking God’s judgment upon yourself. That is why many of you are weak and sick and some have even died.