What does Acts 10:15 mean?
Peter is on a rooftop outside the town of Joppa on the coast of the Mediterranean Sea, east and a bit north of Jerusalem. As he prays, he has a vision of a sheet with different types of animals dropping from heaven. A voice tells him to kill and eat the animals, but some of the animals are unclean—prohibited by the Mosaic law—so he refuses (Acts 10:9–14)."Common" is from the Greek root word koinos. Like the English term common, it literally means "ordinary," but it's often used to describe something unrefined, vulgar, or low-class. In that sense, to the Jews, it means ceremonially unclean: not fit for the worship of God. It is something that is not holy. If someone touched or ate or did something "unclean," they were prohibited from coming to the temple to worship. Some things, like moving a dead body, were inevitable. Some, like eating unclean foods, were avoidable and religiously attended to. That which is "unclean" is not necessarily evil, or sinful, in and of itself; it's simply prohibited.
Peter has already witnessed Jesus putting unclean food into its proper perspective. The Pharisees had confronted Jesus because His disciples didn't ceremonially wash their hands before they ate (Matthew 15:1–11). The Pharisees did so in case they had accidentally touched something that had been touched by someone who was unclean—they didn't want that uncleanness to get inside of them. This attitude assumed that it was the literal physical substance, itself, which carried uncleanness, regardless of a person's intentions.
Jesus responded in frustration. He knew those religious leaders would rather follow manmade rules than do something as obvious and as God-ordained as properly take care of their elderly parents. Jesus pointed out that true uncleanness comes from the sin in a person's heart, not from what physical thing they put in their bodies. He graphically pointed out that even clean food would eventually come out the other end! Mark, who likely got the information for his Gospel from Peter, explained that Jesus' illustration was His declaration that there were no more unclean foods (Mark 7:1–23).
Mark followed a line of logic from unclean hands, to unclean hearts, to an understanding that the kosher dietary laws were fulfilled and no longer in force. Peter's vision and application goes from unclean foods, to unclean dinner mates, to salvation to the Gentiles. The food the Jews eat is a part of the deeply cultural tradition of the meal. To share a meal with someone is to publicly declare your allegiance with them. This is why the Pharisees were so offended when Jesus ate with tax collectors and sinners (Mark 2:13–17). The vision and Peter's impending company (Acts 10:17–23) teach Peter that what had been "unclean"—prohibited food, prohibited company, prohibited friends—has now been made clean through Jesus' sacrifice.
This is an extremely difficult lesson for Peter. He does go to the Gentiles (Acts 10:23–33), he does share Jesus' story with them (Acts 10:34–48), and he does defend his actions to the other Jewish Jesus-followers in leadership in Jerusalem (Acts 11:1–18). But years later, visiting the church in Syrian Antioch, he forgets. He gets influenced by the legalistic Jewish Jesus-followers and withdraws from Gentile company. Paul sets him straight, but it shows how incredibly hard it was for the Jews to accept that Jesus is for everyone (Galatians 2:11–14).
