ANSWER: There are at least SEVENTEEN appearances of angels listed in the Gospel accounts and the rest of the New Testament.
An angel appears to Zacharias the priest declaring he will have a son to be named John (John the Baptist).
11. Then an angel of the Lord appeared to him, standing at the right side of the altar of incense. 12. And when he saw the angel, Zacharias was troubled, and fear fell upon him. 13. But the angel said to him, "Fear not, Zacharias, because your supplication has been heard; and your wife Elizabeth shall bear a son to you, and you shall call his name John. (Luke 1)
An angel from God tells a virgin named Mary she will give birth to the savior of mankind (Luke 1:26-28, 30-31). Joseph receives at least three separate visits from angels - one regarding marrying Mary and to concerning the protection of baby Jesus (Matthew 1:18-20, 2:12-13, 19-21) They also appeared twice to shepherds near Bethlehem regarding the birth of Jesus (Luke 2:8-11, 13-14). One of the angelic host came and ministered to Jesus after his temptation by the devil.
3. And when the tempter came to Him, he said, "If You are the Son of God, command that these stones become bread. 11. Then the devil left Him; and behold, angels came and ministered to Him. (Matthew 4)
From time to time an angel would stir the water in the pool of Bethesda. The first person to enter the pool after the angel stirred it would be healed of their diseases (John 5:1-4). God also sent an angel to Jesus to strengthen him before his suffering and death.
When He came to the place, He said to them, "Pray that you may not enter into temptation." . . . Then an angel appeared to Him from heaven, strengthening Him." (Luke 22:39, 43)
An angel appears twice near Jesus' tomb declaring he has already risen from the dead (Matthew 28:1-2, 5-6, (Mark 16:5-6). Two angels declare to the disciples, right after Jesus ascends to heaven, that he will return to the earth in the same way they saw him leave (Acts 1:10 - 11).
An angel frees the apostles from prison (Acts 5:17-20) and also appears to a Gentile named Cornelius telling him to send for the apostle Peter.
1. Now there was in Caesarea a certain man named Cornelius, a centurion of a band that is called the Italian band, 2. A devout man who also feared God with all his house, both in giving many alms to the people and in beseeching God continually in prayer. 3. He clearly saw in a vision, about the ninth hour of the day, an angel of God coming to him and saying to him, "Cornelius."
4. But as he fixed his eyes on him, he became afraid and said, "What is it, Lord?" And he said to him, "Your prayers and your alms have gone up for a memorial before God. 5. And now send men to Joppa, and call for Simon who is surnamed Peter. (Acts 10)
One of God's spiritual servants is sent to free Peter from prison.
5. As a result, Peter was securely held in the prison, but fervent prayer was made to God by the church for him.7. But suddenly an angel of the Lord stood by him, and a light shined in the building. And after striking Peter on the side, he roused him, saying, "Get up! Hurry!" And the chains fell off his hands. (Acts 12)
Lastly, one of God's angels is sent to tell the apostle Paul that he and those with him on the ship will not lose their lives at sea (Acts 27:1-2, 21-24).