1 Corinthians 10:16-17

10:16 The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ? 10:17 For we [being] many are one bread, [and] one body: for we are all partakers of that one bread.

1 Corinthians 10:21

10:21 Ye cannot drink the cup of the Lord, and the cup of devils: ye cannot be partakers of the Lord’s table, and of the table of devils.