Their existence was taken for granted by the biblical authors. The use of the word angel may have been a way of describing what was believed to be an appearance of God himself in human form. They either have no body or one that is only apparent. New Testament statements about angels reflect Jewish views of these beings. During the Middle Ages, theologians developed a hierarchy of angels.
Angels are a popular subject in folklore, literature, and art.
All religions are concerned with the relationship human beings have or may have with the supernatural realm. In ancient Greek religion, in Judaism and Christianity, and in Islam this relationship is thought to involve angels-divine messengers sent to humans to instruct, inform, or command them. An angel can function also as a protective guardian, as a heavenly warrior, and even as a cosmic power. Moreover, the line between a good angel and a bad angel, or demon, is sometimes unclear. Hence, angels can be broadly described as personified powers mediating between the divine and the human.