He and all his family were devout and God-fearing; he gave generously to those in need and prayed to God regularly. One day at about three in the afternoon he had a vision. He distinctly saw an angel of God, who came to him and said, "Cornelius!" Cornelius stared at him in fear. "What is it, Lord?" he asked. The angel answered, "Your prayers and gifts to the poor have come up as a memorial offering before God.

Acts 10:2-4 from New International Version (NIV)
 

One day at about three in the afternoon he had a vision. He distinctly saw an angel of God, who came to him and said, "Cornelius!" Cornelius stared at him in fear. "What is it, Lord?" he asked. The angel answered, "Your prayers and gifts to the poor have come up as a memorial offering before God. Now send men to Joppa to bring back a man named Simon who is called Peter.

Acts 10:3-5 from New International Version (NIV)
 

He is staying with Simon the tanner, whose house is by the sea." When the angel who spoke to him had gone, Cornelius called two of his servants and a devout soldier who was one of his attendants. He told them everything that had happened and sent them to Joppa.

Acts 10:6-8 from New International Version (NIV)
 

Peter went down and said to the men, "I'm the one you're looking for. Why have you come?" The 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." Then 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.

Acts 10:21-23 from New International Version (NIV)
 

The Spirit told me to have no hesitation about going with them. These six brothers also went with me, and we entered the man's house. He told us how he had seen an angel appear in his house and say, `Send to Joppa for Simon who is called Peter. He will bring you a message through which you and all your household will be saved.'

Acts 11:12-14 from New International Version (NIV)

Suddenly an angel of the Lord appeared and a light shone in the cell. He struck Peter on the side and woke him up. "Quick, get up!" he said, and the chains fell off Peter's wrists. Then the angel said to him, "Put on your clothes and sandals." And Peter did so. "Wrap your cloak around you and follow me," the angel told him. Peter followed him out of the prison, but he had no idea that what the angel was doing was really happening; he thought he was seeing a
vision.

Acts 12:7-9 from New International Version (NIV)
 

Then the angel said to him, "Put on your clothes and sandals." And Peter did so. "Wrap your cloak around you and follow me," the angel told him. Peter followed him out of the prison, but he had no idea that what the angel was doing was really happening; he thought he was seeing a vision. They passed the first and second guards and came to the iron gate leading to the city. It opened for them by itself, and they went through it. When they had walked the length of one street, suddenly the angel left him.

Acts 12:8-10 from New International Version (NIV) 

Peter followed him out of the prison, but he had no idea that what the angel was doing was really happening; he thought he was seeing a vision. They passed the first and second guards and came to the iron gate leading to the city. It opened for them by itself, and they went through it. When they had walked the length of one street, suddenly the angel left him. Then Peter came to himself and said, "Now I know without a doubt that the Lord sent his angel and rescued me from Herod's clutches and from everything the Jewish people were anticipating."

Acts 12:9-11 from New International Version (NIV)
 

They passed the first and second guards and came to the iron gate leading to the city. It opened for them by itself, and they went through it. When they had walked the length of one street, suddenly the angel left him. Then Peter came to himself and said, "Now I know without a doubt that the Lord sent his angel and rescued me from Herod's clutches and from everything the Jewish people were anticipating." When this had dawned on him, he went to the house of Mary the mother of John, also called Mark, where many people had gathered and were praying.

Acts 12:10-12 from New International Version (NIV) 

When she recognized Peter's voice, she was so overjoyed she ran back without opening it and exclaimed, "Peter is at the door!" "You're out of your mind," they told her. When she kept insisting that it was so, they said, "It must be his angel." But Peter kept on knocking, and when they opened the door and saw him, they were astonished.

Acts 12:14-16 from New International Version (NIV)
 

They shouted, "This is the voice of a god, not of a man." Immediately, because Herod did not give praise to God, an angel of the Lord struck him down, and he was eaten by worms and died. But the word of God continued to increase and spread.

Acts 12:22-24 from New International Version (NIV)

When he said this, a dispute broke out between the Pharisees and the Sadducees, and the assembly was divided. (The Sadducees say that there is no resurrection, and that there are neither angels nor spirits, but the Pharisees acknowledge them all.) There was a great uproar, and some of the teachers of the law who were Pharisees stood up and argued vigorously. "We find nothing wrong with this man," they said. "What if a spirit or an angel has spoken to him?"

Acts 23:7-9 from New International Version (NIV)
 

(The Sadducees say that there is no resurrection, and that there are neither angels nor spirits, but the Pharisees acknowledge them all.) There was a great uproar, and some of the teachers of the law who were Pharisees stood up and argued vigorously. "We find nothing wrong with this man," they said. "What if a spirit or an angel has spoken to him?" The dispute became so violent that the commander was afraid Paul would be torn to pieces by them. He ordered the troops to go down and take him away from them by force and bring him into the barracks.

Acts 23:8-10 from New International Version (NIV)
 

But now I urge you to keep up your courage, because not one of you will be lost; only the ship will be destroyed. Last night an angel of the God whose I am and whom I serve stood beside me and said, `Do not be afraid, Paul. You must stand trial before Caesar; and God has graciously given you the lives of all who sail with you.

Acts 27:22-24 from New International Version (NIV)