'Real' in the Bible

Now concerning eating food offered to idols: We know that no idol is real in this world and that there is only one God.

However, not all [believers] have this knowledge. But some, being accustomed [throughout their lives] to [thinking of] the idol until now [as real and living], still eat food as if it were sacrificed to an idol; and because their conscience is weak, it is defiled (guilty, ashamed).

For if any one were to see you, who know the real truth of this matter, reclining at table in an idol's temple, would not his conscience (supposing him to be a weak believer)

This is my defense to those who would put me on trial and interrogate me [concerning my authority as an apostle]:

Do I mean that a thing sacrificed to an idol is what it claims to be, or that an idol is a real thing?