Omg I think I did a meme like this at one point and you questioned the exact same thing.
Magic is the manipulation of the things around you by your own will. Miracles are impossible instances made possible by God. I believe in miracles because I believe God can, of course, break his own rules, but not in magic because man cannot break the boundaries set for him of his own accord.
Angels and demons don't have superpowers, they simply have different abilities than ours, which I guess you could consider "stronger". As for super-strength and such, that's not magic, it's biologically explainable.