We can determine from the Bible that immortal angels are:

(i) God's "ministering spirits" who look after His creation, particularly His children: "Are not all angels ministering spirits sent to serve those who will inherit salvation?" (Hebrews 1:14).

(ii) They are immortal: "…those who are considered worthy of…the resurrection…can no longer die, for they are like the angels." (Luke 20:35-36; and see Mark 12:25).

(iii) Although normally invisible to human eyes, angels can appear as men and be seen by humans: "Do not forget to entertain strangers, for by so doing some people have entertained angels without knowing it." (Hebrews 13:1-2). This points to the incident recorded in Genesis ch.18 (see above) when Abraham was visited by angels without realising at first that they were not men.

We are not told of the origin of angels, but they may have been God's executives in the work of creation (see Genesis 1:26). Regarding their status, the writer to the Hebrews tells us that Jesus, as a man, was made "a little lower than the angels" (Hebrews 2:7-10), and that after his death and resurrection, Jesus became "as much superior to the angels as the name he has inherited is superior to theirs." (Hebrews 1:4). They always obey God's will perfectly, but do not necessarily act on their own initiative.

Also Paul reproves and encourages the Corinthian Christians by reminding them that those who attain to God's kingdom will be responsible for judging (or directing the work of?) the angels (in 1 Corinthians 6:3). Those raised from the dead and made immortal as Jesus was, will, like him, be "like the angels in heaven" (Matthew 22:30).

As to how many angels there are, Christ, before his arrest said that he could call on "twelve legions of angels" (there were, in theory, 6,000 men in a Roman Legion), and Matthew 18:10 seems to indicate that we may each have our own 'guardian angel' to look after our welfare: "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".

Abraham
Acts of the Apostles
Adam
Adoption
Affliction
Age, Aion
Almighty God
Altar
Amen
Angel
  1. Human angels
  2. "The angels who sinned"
  3. Immortal angels
  4. "Fallen angels"
  5. "Evil angels"
Anger
Anointing
Antichrist
Apocrypha
Apostasy
Apostle
Archangel
Ark
  1. Ark constructed by Noah
  2. Ark of the Covenant
Armageddon
Ascension
Assyria
Astrology
Atonement