'Abstain from' in the Bible

It is true that a particular kind of food will not bring us into God's presence; we are neither inferior to others if we abstain from it, nor superior to them if we eat it.

Or I only and Barnabas, have we not a right to abstain from labor?

But if any one tells you, "This food has been offered in sacrifice;" abstain from eating it--out of respect for him who warned you, and, as before, for conscience' sake.