Are they entities or symbolic?
Charles Fillmore defines angels as "the projection into consciousness of a spiritual idea direct from the Fountainhead, Jehovah" (The Revealing Word). An angel, he adds, is "the word of Truth, in which is centered the power of God to overcome all limited beliefs and conditions."
Angels in the Bible, then, are representations of divine ideas. They are generally depicted as visitors from a realm of Spirit. They interact with Abraham; they go up and down Jacob's ladder; they visit Mary, Joseph, shepherds, and others to launch the story of the birth of Jesus. Metaphysically, we would say they are not beings; they are ideas. And yet...
Is it possible that a spiritual being may make itself known in order to communicate a divine idea at precisely the time that it's needed? Would that be inconsistent with Charles Fillmore's definition? I don't think so, which is only my opinion. Others may (and do) think otherwise. I don't think there is any inconsistency at the dimension of Truth between a disembodied divine idea direct from Source and a divine idea expressed by an angelic presence.