The following is an excerpt from The MacArthur New Testament Commentary on 1 Corinthians 8.

But food will not commend us to God; we are neither the worse if we do not eat, nor the better if we do eat. But take care lest this liberty of yours somehow become a stumbling block to the weak. For if someone sees you, who have knowledge, dining in an idol’s temple, will not his conscience, if he is weak, be strengthened to eat things sacrificed to idols? For through your knowledge he who is weak is ruined, the brother for whose sake Christ died. And thus, by sinning against the brethren and wounding their conscience when it is weak, you sin against Christ. (8:8–12)The third truth with which Paul agreed was that eating or not eating food has no spiritual significance in itself. Neither act will commend us to God. Commend (paristemi) means “to place near, bring beside, present to.” Neither eating or not eating food will bring us closer to God or make us approved by Him. The general point is that doing things not forbidden by God has no significance in our relationship to Him. They are spiritually neutral. Food is an excellent illustration of that fact.

Common sense and concern for the bodies God has given us should make us careful about what and how much we eat. Gluttony is harmful and eating foods to which we are allergic is harmful. No sensible, mature person will do those things. But, in itself, eating or not eating certain foods has absolutely no spiritual significance. Jesus made it plain that “there is nothing outside the man which going into him can defile him; but the things which proceed out of the man are what defile the man” (Mark 7:15). The Lord’s command to Peter to “kill and eat” was both figurative, referring to accepting Gentiles, and literal, referring to eating food previously considered ceremonially unclean (Acts 10:10–16; cf. v. 28). And Paul told Timothy to receive all food with thankfulness (1 Tim. 4:4).

Food makes no difference for food’s sake, for ceremony’s sake, or for God’s sake. But it can make a great difference for the sake of the conscience of some of His children. What would not otherwise be wrong for us becomes wrong if it is a stumbling block to the weak. Obviously, some Corinthian believers could not handle such liberty; it would pull them down into the pit from which they had been delivered. If an immature brother sees us doing something that bothers his conscience, his spiritual life is harmed. We should never influence a fellow Christian to do anything that the Holy Spirit, through that person’s conscience, is protecting him from.

A mature believer rightly sees no harm for himself in dining in an idol’s temple in some family or community event. He does not accept the pagan beliefs or participate in the pagan practices, but he can associate with pagan people because he is spiritually strong; he has spiritual knowledge.

But if a Christian who has a conscience that is weak sees a mature believer eating in the temple, the weak brother is likely to be tempted to go against his own conscience and to eat in the temple himself. That could be dangerous to him, causing him to go against his own conscience. Consequently, through your knowledge he who is weak is ruined, the brother for whose sake Christ died. Ruined has the idea of “to come to sin.” We cause that person to sin by leading him into a situation he cannot handle.

It is never right to cause another believer to violate his conscience. To do so runs the risk of ruining a brother for whose sake Christ died (cf. Acts 20:28; 1 Pet. 1:18–19). Our Christian liberty must never be used at the expense of a Christian brother or sister who has been redeemed at such a price.

The voice of a Christian’s conscience is the instrument of the Holy Spirit. If a believer’s conscience is weak it is because he is spiritually weak and immature, not because the leading of his conscience is weak. Conscience is God’s doorkeeper to keep us out of places where we could be harmed. As we mature, conscience allows us to go more places and to do more things because we will have more spiritual strength and better spiritual judgment.

A small child is not allowed to play with sharp tools, to go into the street, or to go where there are dangerous machines or electrical appliances. The restrictions are gradually removed as he grows older and learns for himself what is dangerous and what is not.

God confines His spiritual children by conscience. As they grow in knowledge and maturity the limits of conscience are expanded. We should never expand our actions and habits before our conscience permits it. And we should never encourage, either directly or indirectly, anyone else to do that. By sinning against the brethren and wounding their conscience when it is weak, you sin against Christ. Causing a brother to stumble is more than an offense against him; it is an offense against our Lord. That is a strong warning. Surely no believer would desire to sin against Christ.

We should be eager to limit our liberty at any time and to any degree in order to help a fellow believer—a brother whom we should love, and a precious soul for whom Christ died.