Do not forget to entertain strangers, for by so doing some people have entertained angels without knowing it. ~ Hebrews 13:2

• Angels were created as a higher order of creatures in the universe than humans are. Therefore, innately they possess greater knowledge.
  

  What is man that you are mindful of him, … You made him a little lower than the heavenly beings and crowned him with glory and honor. ~ Psalm 8:4-5

• Angels study the Bible and the world more thoroughly than humans do and gain knowledge from it
  ~ James 2:19; Revelation 12:12.
• Angels gain knowledge through long observation of human activities. Unlike humans, angels do not have to study the past; they have experienced it. Therefore, they know how others have acted and reacted in situations and can predict with a greater degree of accuracy how we may act in similar circumstances.

• Praise God ~ Psalm 148:1,2; Isaiah 6:3
• Worship God ~ Hebrews 1:6; Revelation 5:8-13
• Rejoice in what God does ~ Job 38:6-7
• Serve God ~ Psalm 103:20; Revelation 22:9
• Carry God's messages
  

  An angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were terrified. But the angel said to them, 'Do not be afraid. I bring you good news of great joy that will be for all the people. ~ Luke 2:9-10

• Appear before God ~ Job 1:6; 2:1
• Are instruments of God's judgments ~ Revelation 7:1; 8:2
• Bring answers to prayer ~ Acts 12:5-10
• Aid in winning people to Christ ~ Acts 8:26; 10:3
• Observe Christian order, work, and suffering
  ~ 1 Corinthians 4:9; 11:10; Ephesians 3:10; 1 Peter 1:12
• Encourage in times of danger ~ Acts 27:23,24
• Care for the righteous at the time of death ~ Luke 16:22
• Are special guardians
  

  Beware that you don't look down upon a single one of these little children. For I tell you that in heaven their angels have constant access to My Father. ~ Matthew 18:10

• Provide protection
  

  For 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 91:10-11

• Rescue from danger
  

  For the angel of the Lord guards and rescues all who reverence Him. ~ Psalm 34:7

And now Christ is in heaven, sitting in the place of honor next to God the Father, with all the angels and powers of heaven bowing before Him and obeying Him. ~ I Peter 3:22

Bless the Lord, you mighty angels of His who carry out His orders, listening for each of His commands. Yes, bless the Lord, you armies of His angels who serve Him constantly. ~ Psalm 103:20-21

"Then I looked and heard the voice of many angels, numbering thousands upon thousands, and ten thousand times ten thousand." ~ Revelation 5:11

For the Son of Man is going to come in his Father's glory with His angels . . And He will send His angels with a loud trumpet call, and they will gather His elect from the four winds, from one end of the heavens to the other. ~ Matthew 16:27 and 24:31