[1Co 11:27, 29 NKJV] 27 Therefore whoever eats this bread or drinks [this] cup of the Lord in an unworthy manner will be guilty of the body and blood of the Lord. ... 29 For he who eats and drinks in an unworthy manner eats and drinks judgment to himself, not discerning the Lord's body.
[1Co 10:21 NKJV] 21 You cannot drink the cup of the Lord and the cup of demons; you cannot partake of the Lord's table and of the table of demons.