What could the old man symbolize? Does he symbolize different things to the characters in the story and to readers?

The old man is an angel, and yet, except for his wings, he is seen as ordinary. In my opinion, the angel serves as a symbol of humanity, imperfect, but capable of great things.... both human and supernatural.

From another point of view, we might also consider the reactions to the angel as a type of symbolism. He represents the unknown... did he arrive to take the child to heaven, or did he arrive to heal her? Do the people truly believe in angels, or do they merely wish to explain his presence? He is revered, but later those same people who revered him turn their backs on him and jeer. The church launches an investigation, and the people sell tickets.