Angels prevent harm coming to God's servants

In Daniel 6:22 Daniel says to the king "My God sent his angel, and he shut the mouths of the lions. They have not hurt me, because I was found innocent in his sight. Nor have I ever done any wrong before you, Your Majesty." Whether Daniel saw anything or not he certainly believed, and this is now in Scripture, that it was angels who keep the mouths of the lions shut so that they did not harm God's servant. No doubt angels often intervene so that God's servants are kept from harm.

Wesley comments on Daniel 6:22 "See the power of God over the fiercest creatures! See the care God takes of his faithful servants, especially when they are called to suffer for him! See how ready the angels are to minister to the heirs of salvation!"

Joseph Exell says "The text in Daniel suggests the whole doctrine of angel-ministration. That imperilled life guarded by a sentinel from heaven is no solitary spectacle. It has many parallels. There had been the ministration of angels before, as there has been a thousand times since."

Angels mass in heaven to worship God with believers

Hebrews 12:22, 23 But you have come to Mount Zion, to the city of the living God, the heavenly Jerusalem. You have come to thousands upon thousands of angels in joyful assembly, to the church of the firstborn, whose names are written in heaven. You have come to God, the Judge of all, to the spirits of the righteous made perfect ...

Angels strengthened Jesus as he came to the cross

Luke 22:43 An angel from heaven appeared to him and strengthened him.

Matthew 26:53 Do you think I cannot call on my Father, and he will at once put at my disposal more than twelve legions of angels?

Only Luke mentions this. As the angel appeared only to Jesus it may be wondered how Luke knew. It is suggested that such a change came over the Saviour that it was obvious to the disciples who then passed it on, Luke discovering ti when he wrote his Gospel.

Matthew Henry says of how when Christ was in his agony and there appeared to him an angel from heaven, strengthening him that this was a part of his humiliation - that he was thus strengthened by a ministering spirit.

Angels tell people not to be afraid when they appear

Genesis 21:17 God heard the boy crying, and the angel of God called to Hagar from heaven and said to her, "What is the matter, Hagar? Do not be afraid; God has heard the boy crying as he lies there.
Luke 1:13 But the angel said to him: "Do not be afraid, Zechariah; your prayer has been heard. Your wife Elizabeth will bear you a son, and you are to call him John.

Luke 1:30 But the angel said to her, "Do not be afraid, Mary; you have found favor with God. 

Luke 2:10 But the angel said to them, "Do not be afraid. I bring you good news that will cause great joy for all the people. 

Matthew 28:5 The angel said to the women, "Do not be afraid, for I know that you are looking for Jesus, who was crucified. 

Angels often startle people and make them afraid when they appear

Daniel 10:4-8  On the twenty-fourth day of the first month, as I was standing on the bank of the great river, the Tigris, I looked up and there before me was a man dressed in linen, with a belt of fine gold from Uphaz around his waist. His body was like topaz, his face like lightning, his eyes like flaming torches, his arms and legs like the gleam of burnished bronze, and his voice like the sound of a multitude. I, Daniel, was the only one who saw the vision; those who were with me did not see it, but such terror overwhelmed them that they fled and hid themselves. So I was left alone, gazing at this great vision; I had no strength left, my face turned deathly pale and I was helpless.
Luke 1:12 When Zechariah saw him, he was startled and was gripped with fear. 

Luke 2:9 An angel of the Lord appeared to them (the shepherds), and the glory of the Lord shone around them, and they were terrified.

Matthew 29:2-4 There was a violent earthquake, for an angel of the Lord came down from heaven and, going to the tomb, rolled back the stone and sat on it. His appearance was like lightning, and his clothes were white as snow. The guards were so afraid of him that they shook and became like dead men.

Gill notes how in the case of Zechariah he was troubled, and fear fell upon him; for such appearances of angels were not now so common as formerly: and when they were more usual, generally had such effects on the minds, even of good men and in the case of the shepherds - at the sight of such a personage, and at such unusual light and glory about them: they ... not used to such appearances ... were awed with the majesty of God, of which these were symbols, and were conscious to themselves of their own sinfulness and frailty.

Angels are all in submission to Jesus Christ

1 Peter 3:22 ... who has gone into heaven and is at God's right hand - with angels, authorities and powers in submission to him. 

After his resurrection Jesus ascended to heaven where he now sits on God's right hand. Every angel and every authority, clean and unclean, is subject and submissive to him. He is their Lord.

Angels are to be honoured but not worshipped

Revelation 19:10 At this I fell at his feet to worship him. But he said to me, "Don't do that! I am a fellow servant with you and with your brothers and sisters who hold to the testimony of Jesus. Worship God! For it is the Spirit of prophecy who bears testimony to Jesus." 

Angels are wonderful creatures and it is tempting, if one sees them in all their glory, to worship them but they are not to be worshipped. Only God is to be worshipped.