1 Corinthians 10:27
If any of them that believe not bid you [to a feast], and ye be disposed to go; whatsoever is set before you, eat, asking no question for conscience sake.
Note 4 at 1Co 10:27: Although this is incidental to the point Paul was making, it is interesting to note that Paul did not forbid Christians associating with nonbelievers. Some religious groups today would feel contaminated through association with people who do not believe and live like them. That is not the example of Paul or of Jesus.