There are two kinds of beings in heaven who are called angels: those who are spirits and those who have bodies of flesh and bone. Angels who are spirits have not yet obtained a body of flesh and bone, or they are spirits who have once had a mortal body and are awaiting resurrection. Angels who have bodies of flesh and bone have either been resurrected from the dead or translated.
There are many references in scripture to the work of angels. Sometimes angels speak with a voice of thunder as they deliver God’s messages (Mosiah 27:11–16). Righteous mortal men may also be called angels (JST, Gen. 19:15 [Appendix]). Some angels serve around the throne of God in heaven (Alma 36:22).
The scriptures also speak of the devil’s angels. These are those spirits who followed Lucifer and were thrust out of God’s presence in the premortal life and cast down to the earth (Rev. 12:1–9; 2 Ne. 9:9, 16; D&C 29:36–37).