In Short

1

Angels are spiritual beings.

“Are not all angels ministering spirits sent to serve those who will inherit salvation?”
Hebrews 1:14

“The angel said to him, ‘I am Gabriel. I stand in the presence of God, and I have been sent to speak to you and to tell you this good news.'”
Luke 1:19

“Suddenly a great company of the heavenly host appeared with the angel, praising God and saying, ‘Glory to God in the highest heaven, and on earth peace to those on whom his favor rests.’ When the angels had left them and gone into heaven…”
Luke 2:13-15

2

Some angels are evil and try to lead us away from God, such as Satan.

“Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. Resist him, standing firm in the faith, because you know that the family of believers throughout the world is undergoing the same kind of sufferings.”
1 Peter 5:8-9

“And the angels who did not keep their positions of authority but abandoned their own home—these he has kept in darkness, bound with everlasting chains for judgment on the great Day.”
Jude 6

3

But God has command over all angels, including the good angels who help God’s people.

“See that you do not look down on one of these little ones. For I tell you that their angels in heaven always see the face of my Father in heaven.”
Matthew 18:10

“He will command his angels concerning you
to guard you in all your ways;
they will lift you up in their hands,
so that you will not strike your foot against a stone.”
Psalm 90:11-12