"Talking with him, Peter went inside and found a large gathering of people. He 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. So, when I was sent for, I came without raising any objection. May I ask why you sent for me?'" NIV translation
In this passage, we see that Peter understood the lesson that God taught him with the vision. That lesson, as he explains to the people at Cornelius' house, was that he was not to judge people by their race. The lesson is as true for us as it was for him. As Christians, we know that Christ paid the debt for all men and therefore we are all one in Christ.
"Cornelius answered, 'Four days ago I was in my house praying at this hour, at three in the afternoon. Suddenly a man in shining clothes stood before me and said, "Cornelius, God has heard your prayer and remembered your gifts to the poor. Send to Joppa for Simon who is called Peter. He is a guest in the home of Simon the tanner, who lives by the sea." So I sent for you immediately, and it was good of you to come. Now we are all here in the presence of God to listen to everything the Lord has commanded you to tell us.'" NIV translation
In this passage, Cornelius explains to Peter that God told him to send for Peter. He explains how God spoke to him and told him what to do and that Cornelius was simply obeying. We also learn from this passage that Cornelius was strong in his faith.
We see that, because of his faith, Cornelius spent regular time in prayer, gave gifts to the poor, and saw God at work in his life. He trusted that God had spoken to Peter and told him to come as well as told him the message to share.
"Then Peter began to speak: 'I now realize how true it is that God does not show favoritism but accepts men from every nation who fear him and do what is right.'" NIV translation
What a lesson for all mankind in this simple passage. Peter states it as clear as can be that God loves all men. How can it be that we still have racism even in the church? As Christians, we are one in Christ!
"'You know the message God sent to the people of Israel, telling the good news of peace through Jesus Christ, who is Lord of all. You know what has happened throughout Judea, beginning in Galilee after the baptism that John preached- how God anointed Jesus of Nazareth with the Holy Spirit and power, and how he went around doing good and healing all who were under the power of the devil, because God was with him.'" NIV translation
Now, Peter begins to teach the people that are gathered at Cornelius' house. He starts by reminding them of Jesus being baptized by John and the Spirit descending on him. He reminds them of how Jesus drove out demons and worked with the very power of God. This is a very important reminder for us today as well. It should remind us that we can have that same power that is mentioned here. There is one Spirit and that very Spirit that was given to Jesus is given to us as well when we accept the work that Jesus did on the cross.