In one of his poems, John Milton said: ‘Millions of spiritual creatures walk the earth, unseen both when they wake and when they sleep’. The teaching about angels is one of the intriguing things of biblical faith. It is mysterious.
Yet it is clear from the Bible that there are a finite number of created spirits, evil (fallen) and elect (holy). It seems they are not so limited in movement as human beings. There is ‘behind-the-scenes’ activity of both unfallen angels and demons, including Satan their chief (Ephesians 6:12).
References to them are found all over the Bible. Sometimes they take visible form; for example, the three visitors to Abraham at Mamre, foretelling the birth of Isaac (Genesis 18). It is probably to this the writer to the Hebrews refers in 13:2: ‘entertaining angels unawares’.
