Matthew 18:10

Because a great and hard-to-count host of demons wanders this whole world, overturning our affairs by many kinds of deceit, Christ has set tutors over us from heaven — not as if human nature were inferior (far from it; they are far above what is ours, and the point is clear), but as ones who oppose demonic greed with their own strength and are able to contend for our life. With everything else, Christ has also set this right for our souls.

Long ago, when we were ruined, heaven was shut, and the angels took no account of any of us, as if sharing the Master of all’s indignation at the insult. But when God was pleased “to sum up all things in Christ,” he came to earth, brought the holy angels down, and appointed them guardians of our life. That is why he also said, “You will see heaven opened, and the angels of God ascending and descending on the Son of Man” — “of Man,” that is, for the sake of the human. Heaven, shut in the times already past, he opened for us, so that running up and down for our sake they might be servants of the economy accomplished for us through Christ.

Paul too says this: “Are they not all ministering spirits,” and what follows. Jacob our forefather’s dreams have the same force: he saw, as he said, “the ladder” reaching from earth “to heaven,” and <the dream> signifies nothing else, I think, than that in due times there will be ascent and descent for the holy angels because the Only-Begotten shines in the world with flesh for the human. It is most dreadful, then, that those deemed worthy of such care from God — allotted angels as overseers and tutors — should be ranked as of no account, and that by us, their fellow-servants and brothers.