Continuing in 1 Corinthians 10, he circles back to the eating food offered to idols that he started in chapter 6 and again in chapter 8. Here Paul makes the point that taking communion is participating in the body and blood of Christ; therefore, eating food offered to idols is participating with the idol, who represents a demon: 

Therefore, my beloved, flee from idolatry. I speak as to sensible people; judge for yourselves what I say. The cup of blessing that we bless, is it not a participation in the blood of Christ? The bread that we break, is it not a participation in the body of Christ? Because there is one bread, we who are many are one body, for we all partake of the one bread. Consider the people of Israel: are not those who eat the sacrifices participants in the altar? What do I imply then? That food offered to idols is anything, or that an idol is anything? No, I imply that what pagans sacrifice they offer to demons and not to God. I do not want you to be participants with demons. You cannot drink the cup of the Lord and the cup of demons. You cannot partake of the table of the Lord and the table of demons. (1 Corinthians 10.14 – 21, ESV)

Pretty clear-cut, right? Don’t eat food offered to idols. Not so fast. He makes it NOT absolute; it has to do with what the person you’re eating with thinks:

“All things are lawful,” but not all things are helpful. “All things are lawful,” but not all things build up. Let no one seek his own good, but the good of his neighbor. Eat whatever is sold in the meat market without raising any question on the ground of conscience. For “the earth is the Lord’s, and the fullness thereof.” If one of the unbelievers invites you to dinner and you are disposed to go, eat whatever is set before you without raising any question on the ground of conscience. But if someone says to you, “This has been offered in sacrifice,” then do not eat it, for the sake of the one who informed you, and for the sake of conscience—I do not mean your conscience, but his. For why should my liberty be determined by someone else’s conscience? If I partake with thankfulness, why am I denounced because of that for which I give thanks? So, whether you eat or drink, or whatever you do, do all to the glory of God. Give no offense to Jews or to Greeks or to the church of God. (1 Corinthians 10.23 – 32, ESV)

Wow. “All things are lawful” but not all things are helpful or edifying. And if we need any evidence that legalism doesn’t work, this is it. Why not just make a rule? Life would be easier. That’s why systems of legalism develop, isn’t it? But law is always incomplete. That’s why legislatures continue to meet. Legalism as a way of life doesn’t work.

Principles: 

• Let no one seek his own good, but the good of his neighbor.
• Whether you eat or drink, or whatever you do, do all to the glory of God.
• Give no offense to Jews, Gentiles, or the church.
• “Be imitators of me” – “I try to please everyone in everything I do, not seeking my own advantage, but that of many, that they may be saved.”

We who are strong have an obligation to bear with the failings of the weak, and not to please ourselves. Let each of us please his neighbor for his good, to build him up. (Romans 15.1, 2, ESV)