1 Corinthians 10:21
You cannot drink both the Cup of the Lord and the cup of demons. You cannot partake at the Table of the Lord and at the table of demons.
Matthew 6:24
No one can serve two masters, for either he will hate one and love the other, or else he will attach himself to one and despise the other. You cannot serve both God and Money.
1 Corinthians 8:10
For if some one should see you who possess this knowledge, feasting in an idol's temple, will not his conscience, if he is a weak man, become so hardened that he, too, will eat food offered to idols?
1 Corinthians 10:16
In the Cup of Blessing which we bless, is not there a sharing in the blood of the Christ? And in the Bread which we break, is not there a sharing in the Body of the Christ?
2 Corinthians 6:15-17
What harmony can there be between Christ and Belial? or what can those who accept the Faith have in common with those who reject it?