1 Corinthians 10:16-21

The cup of blessing which we bless, is it not a communion of the blood of Christ? The bread which we break, is it not a communion of the body of Christ? seeing that we, who are many, are one bread, one body: for we all partake of the one bread. Behold Israel after the flesh: have not they that eat the sacrifices communion with the altar? What say I then? that a thing sacrificed to idols is anything, or that an idol is anything? But I say, that the things which the Gentiles sacrifice, they sacrifice to demons, and not to God: and I would not that ye should have communion with demons. Ye cannot drink the cup of the Lord, and the cup of demons: ye cannot partake of the table of the Lord, and of the table of demons.