1 Corinthians 10:21
You cannot drink the cup of the Lord and the cup of demons. You cannot eat at the table of the Lord and at the table of demons.
Matthew 6:24
No slave can belong to two masters, for he will either hate one and love the other, or stand by one and make light of the other. You cannot serve God and money.
1 Corinthians 8:10
For if somebody sees you, who are intelligent about this matter, attending a dinner in an idol's temple, will not he, with his sensitive conscience, be led to eat meat that is offered to idols?
1 Corinthians 10:16
Does not the consecrated cup which we bless mean that in drinking it we share in the blood of Christ? Does not the bread that we break mean that in eating it we share in the body of Christ?
2 Corinthians 6:15-17
How can Christ agree with Belial? Or what has a believer in common with an unbeliever?