Since a human form is an assumed form for an angel, and they exist to serve God, I would think they appear in this form for a specific purpose, and once the purpose was fulfilled, they would return to their natural state. They don’t act on their own, they act according to God’s will. If God wanted them to assume a human form for a while to fulfill His purpose, they would do so. However, I doubt there are angels who are permanently walking around in human form. Scripture doesn’t seem to support that. They appeared for specific purposes, such as the example you gave above, or at the Resurrection scene and at the Annunciation and Ascension, for example.
My mother believes she had an encounter with an angel in the guise of a beggar at our door when I was very small. I recall the event because it was so unusual. She believes it was a test of her generosity. My father had abandoned us and she had little food and money, but when the man came to the door (not all that unusual in the 1950’s) she gave him what money she had for food, and thought “Well, at least we have a roof over our heads tonight, he doesn’t have anything.” The man walked down the sidewalk and disappeared before her eyes! The very next day she got a check in the mail for back child support, soon she had a job, and never was in that extreme position again. Always just enough to make ends meet, not much extra, but our needs were met. She was and is a very grateful person, always thanking God for everything. She loves to tell this story.
), but the end of the Middle Ages signalled a change: their beauty came to be increasingly emphasized over their terribility, and the end result is the dainty youths and the babies of latter-day Western art.
