The Almighty brought the Israelites out of Egypt all on His own, according to the Haggadah: “The Lord brought us out of Egypt – not by means of an angel, not by means of any seraph, not by the hands of any messenger, but the Holy One, blessed be He, in His glory, by Himself.”
The passage makes sure that we recognise that Judaism does not believe in middle-men, in intermediaries of any kind (even if they claim to be “the son of God”). Judaism insists that it was not Moses but God who redeemed us from Egypt, and the Haggadah actually eliminates Moses from the story except for one quotation.
It is good theology, but does it accord with the Biblical text? Doesn’t the Torah record the involvement of the Divine angel? In the story of the tenth plague, Exodus 12:22 specifically mentions a destroying angel.
Rashi quotes the Talmudic view that the Almighty would not let the destroying angel pass through Egypt that night to bring destruction to the oppressors and deliverance to the Hebrews, but He did it Himself.
We understand this view, but it still leaves us with the question of why God could have chosen to work through an angel had He so desired, and why the sages are so adamant that He alone – no angel, seraph or messenger – was the deliverer.
It is in order to keep the angels in their place. They sometimes carry out a Divinely-allocated task, but they have no independence of view, status or action. They dare not big-note themselves and imagine they are on a par with God or specially favoured as if they were His sons in a literal sense.
There is a rationalist tradition that actually demotes the angels and almost turns them into spiritual robots. Some thinkers regard angels as a poetical metaphor for the expression of Divine will and power.
There is a great deal that can be said about the doctrine of angels in Judaism, but the Midrash quoted by the Haggadah may be a Midrashic response to Christianity.