In Acts Chapter 10, we read of the gospel going to non-Jews for the first time. The Lord had told His disciples that they would be His witnesses in Jerusalem, Judea, Samaria and then to the ends of the earth. In Chapter 2, they started with the Jews in Jerusalem and Judea. Then in Chapter 8, they went to the Samaritans. And now it was moving to non-Jews for the first time. Peter was given the privilege to open the doors to the Jews and also to the non-Jews.
Cornelius was a man who knew nothing of the Bible or of God. But he was a devout man who prayed to God continually and helped the poor generously(Acts 10:2). An angel appeared to him and told him that both his prayers and his alms had been accepted by God ( Acts 10:4). So we see that God listens to the prayers of non-Christians too, if they are God-fearing and sincere, and He leads them to Christ, Who is the only way to the Father (John.14:6). Many Christians, like Peter, imagine themselves to be superior to non-Christians. But some non-Christians, like Cornelius, are more God-fearing than many Christians. Peter also felt that he was purer than non-Jews. But God had to change Peter's opinion and to enlarge his heart. And God may have to change our opinions about non-Christians too. Peter was so stubborn in his opinion that God had to give him a vision to change his opinion (Acts 10:11). In this vision, Peter saw a sheet containing clean and unclean animals and he heard a voice asking him to kill them and eat them. Peter refused to do so saying he had never eaten anything unclean - because certain animals were unclean according to the law of Moses and Jews were forbidden from eating them (Lev.11).. But God told him not to call anything unclean that God had cleansed. This vision was repeated three times. Peter was perplexed as to the meaning of this vision when the messengers from Cornelius reached Peter's house with the message that an angel had told Cornelius to send for Peter. Then Peter understood that God was telling him to go to the house of this non-Jewish man whom the Jews considered unclean.
The angel who came to Cornelius certainly knew the facts of the gospel - that Christ died for the sins of the world and rose again from the dead. Why didn't he then preach the gospel himself instead of asking Cornelius to call for Peter to come and preach the same message to him? What was it that Peter had that the angel did not have? I am sure the angel could have explained the gospel ten times better than Peter. But Peter had the experience of salvation which the angel did not have. Only a sinner saved by grace can tell another sinner about salvation. That is what we see in the very first verse of Acts: Jesus did and then taught. If you don't have an experience you should not speak about it. Even the angel respected that Divine principle. So never preach what you know but only what you have practiced or at least seeking to practice.
When Peter came to Cornelius' house, he said, "Now I understand that in every nation the man who fears God and does what is right is welcome to Him" (Acts 10:35). (And not only in every nation, but in every denomination too). God welcomes those who fear Him, in every religion and leads them to Christ so that they can be saved. What if Peter had refused to go to Cornelius' house? Would Cornelius have been lost if Peter disobeyed? That would be very unrighteous of God to make Cornelius suffer for Peter's disobedience. If Peter had not gone, God would have sent James or John or someone else to him. If Ananias had not gone to Saul of Tarsus, God would have sent someone else. If you don't go where God tells you to go, God will give your ministry to someone else.
In Acts 10:38, Peter describes Jesus' ministry thus:"Jesus of Nazareth - God anointed Him with the Holy Spirit and with power, and He went about doing good and healing all who were oppressed by the devil, for God was with Him." Even in Jesus' life, it was power that was the evidence of the anointing of the Holy Spirit. And with that power, Jesus did good and delivered people from Satan's oppressions. God fills us with the Spirit so that we too can do good to others and deliver them from Satan's oppression. We are surrounded by people who are oppressed by Satan - people who are discouraged, unhappily married, harassed by their marriage-partners, neglected by their parents, and some even contemplating suicide. God has placed us in the midst of such people so that we can help them to be free from sin and from Satan -and thus be happy. If even Jesus needed to be anointed by the Holy Spirit to fulfil this ministry, how much more we! We read that when Jesus was anointed, "God was with Him." And when we are anointed with the Holy Spirit, God will be with us too. When we stand in the pulpit to preach God's word or when we go to cast out a demon from someone, God will be with us to bless people.