By making this comparison between the Lord’s Supper and sacrifice to idols, and between the Old Testament offerings of the law and sacrifice to idols, Paul might seem to be giving credence to the reality of the idol. If there is communion between the worshipper and the body of Christ, isn’t that because the one being worshipped is a real person? If there is fellowship between the Israelite after the flesh and the altar, isn’t that because the God of the altar is the true God? So then, does this mean that, in order for the same argument to apply, the idol must also have some real existence? But Paul has already said, ‘we know that no idol is anything in the world, and that there is no God but one’ (1 Corinthians 8:4), so he cannot be saying that.