1 Corinthians 10:16-17
10:16 Is not the cup of blessing that we bless a sharing in the blood of Christ? Is not the bread that we break a sharing in the body of Christ?
10:17 Because there is one bread, we who are many are one body, for we all share the one bread.
1 Corinthians 10:21
10:21 You cannot drink the cup of the Lord and the cup of demons. You cannot take part in the table of the Lord and the table of demons.