The passage in Acts 10:12-13 is about both food and people. We need to remember that Peter was Jewish. All of Jesus’ twelve disciples were Jewish. Jesus Himself was Jewish by blood because He was born of Mary and is the Son of David.
Peter kept the Jewish law since childhood and has never eaten anything unclean. However, in this vision God gave Peter, God told Peter to kill and eat unclean animals. But Peter said, “By no means, Lord, for I have never eaten anything unholy and unclean” (Acts 10:14).
But God said, “What God has cleansed, no longer consider unholy” (Acts 10:15).
In this vision, God was testing Peter to see whether Peter would obey Him. Even though Peter called Him “Lord” (Acts 10:14), Peter did not obey God in the vision but kept sticking to his tradition. This happened three times that God told Peter to kill an unclean animal and eat it. But Peter refused three times.
After the vision, Peter kept thinking, wondering what God had meant. Then Gentile men came to Peter’s door sent by the centurion Cornelius. The Holy Spirit told Peter to go with the men so that he could share the gospel with them.
It used to be that Jews did not go with Gentiles to their homes. If a Gentile converts to Judaism, then the Gentile would need to change and come to a Jewish person’s home or a synagogue. What Cornelius was doing was going against tradition and inviting Peter (a Jew) to go to a Gentile’s home (which Jewish people considered unclean).
Through the vision and these interactions, Peter learned that the Lord wants to call all people to Himself (not just the Jews). Because Peter tended to be a bit stubborn, he needed the vision from God first before the Gentiles visited. Otherwise, he might have been inhospitable and refused to go with them.
So this passage is about how Christians are no longer bound by Old Testament laws that restrict food to only clean animals. It tells us that we can eat “all kinds of four-footed animals and crawling creatures of the earth and birds of the air” (Acts 10:12). In the vision, God was telling Peter to be adventurous and start eating what Gentiles ate.
In this passage, God was also telling Peter that no human is unclean. He was telling Peter to not consider the Gentiles unclean, but to go to their homes and share the good news with them.
So Peter finally understood, saying: “I most certainly understand now that God is not one to show partiality, but in every nation the man who fears Him and does what is right is welcome to Him” (Acts 10:34-35).
Acts 10:12-13 is not just about food, it is about this greater concept that God has called us all to be one in Christ. Christ did not die for Jews only, but for both Jews and Gentiles.
These verses are certainly NOT about insinuating to go out to kill people. But God’s vision about the animals got Peter into thinking how he should no longer consider Gentiles as unclean. God’s vision caused Peter to repent.
God used a related subject (such as clean vs unclean food) to get Peter into thinking about the deeper concept of oneness of Jews and Gentiles in Christ.
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When Gentile Christians asked Jewish Christians what part of the Jewish Law they needed to keep, the Holy Spirit gave instructions as follows:
"For it seemed good to the Holy Spirit and to us to lay upon you no greater burden than these essentials:
that you abstain from things sacrificed to idols and from blood and from things strangled and from fornication; if you keep yourselves free from such things, you will do well. Farewell.” (Acts 15:28-29)
So we do not need to keep the ceremonial and food-related laws, except for the ones mentioned above.
The apostle Paul even worried over Christians who were turning back to trying to keep all the Law, saying: “But now that you have come to know God, or rather to be known by God, how is it that you turn back again to the weak and worthless elemental things, to which you desire to be enslaved all over again? You observe days and months and seasons and years. I fear for you, that perhaps I have labored over you in vain.” (Galatians 4:9-11)
“For as many as are of the works of the Law are under a curse; for it is written, 'Cursed is everyone who does not abide by all things written in the book of the law, to perform them.' Now that no one is justified by the Law before God is evident; for, 'The righteous man shall live by faith.' However, the Law is not of faith; on the contrary, 'He who practices them shall live by them.' Christ redeemed us from the curse of the Law, having become a curse for us—for it is written, 'Cursed is everyone who hangs on a tree'— in order that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we would receive the promise of the Spirit through faith." (Galatians 3:10-14)
Furthermore, the Bible says:
“Therefore no one is to act as your judge in regard to food or drink or in respect to a festival or a new moon or a Sabbath day— things which are a mere shadow of what is to come; but the substance belongs to Christ.” (Colossians 2:16-17)
So Christ kept all the Law for us. We cannot possibly keep all the law (especially the ceremonial and food-related ones), and so no one is justified by keeping the law. But we are justified by believing in Christ who kept all the Law as our Substitute.
Therefore, the righteous shall live by faith.
This is not to say that we have a license to sin, but it is saying that our justification does not come from our own works of keeping the law. Our justification comes from Christ who died for us and paid for our sins.
Faith is not just believing or lip service. Faith is believing and learning to be faithful. If we are true Christians, we would have faith in Jesus and be learning how to be faithful to Him too.
What is important to God is not food, drink, or keeping of days, but practicing “love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law” (Galatians 5:22-23).
I do think it is a bit of a push to say that your friend insinuated Acts 10 was about eating people. I think your friend might not have thought about it that way. That’s why he says he didn’t mean it that way.
The best way to help him is to explain what the verses actually mean rather than to show your friend’s position insinuates something absurd.
You can tell him something like the following:
On the surface, the verses show that all foods are edible (whether clean or unclean).
The deeper meaning is about people – that Gentiles are not unclean just as animals are not unclean (because they have been cleansed by God). God wants both Jews and Gentiles to believe.
The purpose of the vision to Peter was to get him to think about his own position and to be softened in his spirit to receive the Gentiles who later came for help.
Your purpose is to help your friend come to the understanding that we as Christians don’t need to keep the Jewish laws regarding foods, festivals, and various ceremonies in order to be holy. You need to show him that these things are only a shadow of things that were to come but the substance is in Christ (Colossians 2:16-17).
Most importantly, you need to explain to him that what is important to God is not food, drink, or keeping of days, but practicing “love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law” (Galatians 5:22-23).
The purpose is to win over your friend to see the truth. The purpose is not to have a good argument. I think we would lose people if we focus on having a good argument, even if we are in the right or the most logical. But God wins people through love. So if you are debating this topic with him, don’t try to win the argument but try to show reasonings through love.
Whether he listens is up to him, but we can pray for him. We can also pray for ourselves that we would speak clearly and say what God wants us to say.