The next change became one of the greatest blessings of the New Covenant, but it involved one of the greatest struggles for Jewish believers. The New Covenant opened the door of fellowship to any believing Gentile (non-Jew). On Pentecost, Peter said as much: “The promise [of salvation and the Spirit] is for you and for your children and for all who are far off, everyone whom the Lord our God calls to Himself” (Acts 2:39). All whom God would call included the Gentiles. Yet that truth, which already was valid because the New Covenant was valid, did not see practical results for some time after Pentecost.
The main reason, again, had to do with people adjusting. They were used to the Old Covenant’s rule that Jews and Gentiles were not to mix socially or religiously. (A Gentile might become a naturalized Jew, and so enter Jewish life, but he could not enter as a Gentile.) When Peter met the Roman solder Cornelius and his family, Peter said, “You yourselves know how unlawful it is for a Jew to associate with or to visit anyone of another nation” (Acts 10:28). Ephesians 2:14-15 called the law of Moses “the dividing wall of hostility.” That massive spiritual barrier had its purpose in its time. It stood for over fifteen centuries. After the death of Christ, the barrier fell and no longer existed in God’s eyes. But that spiritual truth was not yet clear to human eyes. God had to do extraordinary things to open their eyes.
First, God worked on the apostle Peter who held the keys of the kingdom (Matthew 16:19). Peter would be God’s instrument for showing Gentiles the open door into the kingdom, just as he had shown the Jews at Pentecost. God sent a dream to Peter that made it clear to him that he should accept Gentiles. Peter then said to the Roman soldier Cornelius,
God has shown me that I should not call any person common or unclean. So when I was sent for, I came without objection…. Truly I understand that God shows no partiality, but in every nation anyone who fears Him and does what is right is acceptable to Him. (Acts 10:28-29, 34-35)