Read Acts 10:17-29
Context: Peter had been sitting on his roof when he saw a vision of a large sheet being let down to earth that contained all kinds of four-footed animals as well as reptiles and birds. A voice told him to get up, kill and eat.
17While Peter was wondering about the meaning of the vision, the men sent by Cornelius found out where Simon's house was and stopped at the gate. 18They called out, asking if Simon who was known as Peter was staying there.
19While Peter was still thinking about the vision, the Spirit said to him, "Simon, three[a] men are looking for you. 20So get up and go downstairs. Do not hesitate to go with them, for I have sent them."
21Peter went down and said to the men, "I'm the one you're looking for. Why have you come?"
22The men replied, "We have come from Cornelius the centurion. He is a righteous and God-fearing man, who is respected by all the Jewish people. A holy angel told him to have you come to his house so that he could hear what you have to say." 23Then Peter invited the men into the house to be his guests. The next day Peter started out with them, and some of the brothers from Joppa went along. 24The following day he arrived in Caesarea. Cornelius was expecting them and had called together his relatives and close friends. 25As Peter entered the house, Cornelius met him and fell at his feet in reverence. 26But Peter made him get up. "Stand up," he said, "I am only a man myself."
27Talking with him, Peter went inside and found a large gathering of people. 28He said to them: "You are well aware that it is against our law for a Jew to associate with a Gentile or visit him. But God has shown me that I should not call any man impure or unclean. 29So when I was sent for, I came without raising any objection. May I ask why you sent for me?" (NIV)
Acts 10:19 One early manuscript two; other manuscripts do not have the number.
taken from www.biblegateway.com
Up to this point, God had sent the disciples to many different countries, but they were to witness to people like them, the Jews. They shared heritage, culture, and daily rituals.
Cornelius was a perfect person to facilitate the transition of God's salvation to the Gentiles. While he was a centurion in the Italian Regiment, he and his family were God-fearing and they prayed to God regularly. An angel had come to him first, so Cornelius actually initiated the search for the truth instead of the Jewish disciples trying to convince the Gentiles to believe.
With Peter's vision, God was really throwing out the Mosaic Law. Early in Jewish history he had given them many rules about what to eat and how to cook it. Now, out of the blue (literally!!!), he is saying that they can eat everything. Then someone knocks at the door and Peter is called to witness to people who were also considered 'unclean.' I'm not sure we can comprehend the significance of this change. These things were against the law to them, the thought of it was detestable.
But God didn't give Peter much time to think about it...he showed Peter the 'new way' and then thrust him right into the fray!