Cornelius was a Roman centurion of the Italian Cohort stationed at Caesarea Maritima — a 'devout man who feared God with all his household, gave alms liberally, and prayed constantly to God.' An angel appeared to him in a vision and told him to send for Simon called Peter at Joppa.
The next day at Joppa, Peter went up on the rooftop to pray about the sixth hour. He saw a vision: the heavens opened, a great sheet descending with all kinds of animals — including ritually unclean ones. A voice said: 'Rise, Peter; kill and eat.' Peter answered: 'No, Lord; for I have never eaten anything common or unclean.' The voice came again: 'What God has cleansed, you must not call common.' This happened three times. As Peter pondered the meaning, the men sent by Cornelius arrived. Peter went with them to Caesarea.
At Cornelius's house, as Peter preached the gospel, the Holy Spirit fell on all who heard the word — and the Gentiles began speaking in tongues and extolling God. The Jewish believers with Peter were astounded. 'Can anyone forbid water for baptizing these people, who have received the Holy Spirit just as we have?' He commanded them to be baptized. The episode — the 'Gentile Pentecost' — is the decisive opening of the Church to the nations and the prelude to the Council of Jerusalem (Acts 15).