Hebrews 1:7

But God said [this] about the angels [Psa. 104:4 LXX], "He [i.e., God] makes His angels to be [like] winds and His servants [like] flames of fire." [Note: The idea is probably that angels obediently serve God's purpose similar to the way wind and lightening do].

Hebrews 1:14

Are not all angels ministering spirits sent out [by God] to serve those people who will inherit salvation?

Treasury of Scripture Knowledge

Summary

And of the angels he saith, Who maketh his angels spirits, and his ministers a flame of fire.

Bible References

Who

Hebrews 1:14
Are not all angels ministering spirits sent out [by God] to serve those people who will inherit salvation?