Read 1 Corinthians 8 at Bible Gateway.
“However, there is not in everyone that knowledge; for some, with consciousness of the idol, until now eat it as a thing offered to an idol; and their conscience, being weak, is defiled. But food does not commend us to God; for neither if we eat are we the better, nor if we do not eat are we the worse.” 1 Cor 8:7-8
The food that Paul is speaking of in this chapter, is meat (from animal sacrifices) offered to idols:
“Now concerning things offered to idols:” 1 Cor 8:1
“Therefore, if food makes my brother stumble, I will never again eat meat, lest I make my brother stumble.” 1 Cor 8:13
We have to remember that in the 1st century of the Roman Empire, where Corinth was, every butcher shop in the Empire procured its meat from the temples of the idols and the false pagan gods. There was no meat that had not been first offered to an idol as an animal sacrifice. So this created a dilemma among the formerly pagan believers in Jesus outside of Judea: if we eat meat which has been offered to an idol, are we breaking the commandment, Do not commit idolatry?
The discussion is not at all about whether God’s instructions concerning clean and unclean food in Torah have been discarded. It never entered into the church’s head to discard commandments in Torah, especially in light of Jesus’ admonition in Mat 5:17-20, and Paul’s clarification of the position the Torah holds in the life of the believer who has been saved by faith, in Rom 3:31.
The knowledge that Paul is talking about here, that not every believer has, is that idols are nothing – there are no false gods because they don’t exist – and the only God is YHVH Creator of heaven and earth (1 Cor 8:4-6). So therefore, Paul is saying, meat offered to idols is meat offered to nothing, so the believer has perfect liberty to eat meat. But for the believer for whom an idol is something, then if they eat meat which has been offered to it, their conscience has been defiled.
This is the real heart of the matter. Some of us know one thing about God or the Scriptures or the will of God or spiritual matters, and some of us know another thing. Knowledge puffs up. But love edifies, it builds others up. And love is the fulfillment of the Law (Gal 5:14). So if because of superior knowledge, a strong brother eats meat in front of a weak brother, the strong brother by virtue of his strength has encouraged the weak brother to follow his example. The weak are followers, we learned. That is why we do not put children in the care of the ungodly.
When the weak brother follows his example, he defiles his conscience, because he does not have the knowledge that the strong brother has. For him, he has just eaten meat that has been offered to an idol, so he has committed idolatry in his heart.
So even though the strong brother has not sinned in regard to the law of idolatry by eating meat, he has committed another sin almost as grievous, which is wounding the weak conscience of another. The righteousness of the former, of not committing idolatry, is then set next to the unrighteousness of the latter, which is to put a stumbling block in the way of the weak, which is forbidden in Torah because it hurts them, stemming from a lack of love for them (Lev 19:14).
If the weak brother is not eating meat because he loves God fervently and would not transgress the command concerning idolatry in any case, then his righteous deed has proved the greater, because he would not transgress love for the sake of knowledge. The strong brother, on the other hand, who eats meat in front of the weak, has transgressed love for the sake of knowledge. So even though the strong brother might have perfect knowledge of spiritual matters, and of the application of the Law in the life of the believer, he has fallen short of Torah, because he has not shown love.
When Paul says that food does not commend us to God, of course it does not. We have been cleansed and washed by the blood of Messiah Yeshua, whose righteousness does commend us to God! We are no better off if we do eat, or no worse off if we don’t, in regard to being accepted before God. No work of the Law makes us righteous or grants us entrance into the presence of God. This is not different from anything we have already seen Paul say: by the work of the Law no one will be justified in His sight (Rom 3:20)!
However, this is not Paul saying that the dietary law has been abolished! The topic of this discussion has had nothing to do with the dietary law, or clean and unclean food. For we are better off if we do eat according to the dietary law, but not because following the Law commends us to God! It is because blessings follow obedience, and our physical health is protected when we obey God’s instructions concerning what to eat and not eat.