Angels, in a variety of religions, are regarded as spiritual beings. They are often depicted as messengers of God in the Hebrew and Christian Bibles and theQuran. The English word angel is derived from the Greek ἄγγελος (aggelos), a translation of מלאך (mal'akh) in the Hebrew Bible (Tanakh); a similar term, ملائكة(Malāīkah), is used in the Qur'an. The Hebrew and Greek words originally meantmessenger, and depending on the context may refer either to a human messenger (possibly a prophet or priest, such as Malachi, "my messenger", but also for more mundane characters, as in the Greek superscription that the Book of Malachi was written "by the hand of his messenger" (ἀγγήλου)) or to a supernatural messenger, such as the "Mal'akh YHWH," who (depending on interpretation) is either a messenger from God, an aspect of God (such as theLogos), or God Himself as the messenger (the "theophanic angel.")
The term "angel" has also been expanded to various notions of spiritual beingsfound in many other religious traditions. Other roles of angels include protecting and guiding human beings, and carrying out God's tasks.
The theological study of angels is known as angelology. In art, angels are often depicted with wings; perhaps reflecting the descriptions in Revelation 4:6–8 — of the Four Living Creatures (Greek: τὰ τέσσαρα ζῷα) and the descriptions in the Hebrew Bible — of cherubim and seraphim (the chayot in Ezekiel's Merkabahvision and the Seraphim of Isaiah). However, while cherubim and seraphim have wings in the Bible, no angel is mentioned as having wings.

Famous angels and their tasks from the Old Testiment

Individual Angels

1. Michael (translation: who is like God?), performs acts of justice and power
2. Gabriel (translation: the strength of God), performs God's kindness
3. Raphael (translation: God Heals), God's healing force
4. Uriel (translation: God is my light), leads us to destiny
5. Samael (translation: the severity of God), angel of death - see also Malach HaMavet(translation: the angel of death)
6. Sandalphon (translation: bringing together), battles Samael and brings humankind together
7. Camael/Chamuel (translation: one who seeks God), expelled Adam from the Garden of Edenand punishes those who transgress against God
8. Sataniel/Satan (translation: the adversary), tempts humans, serves as an adversary, and brings people's sins before them in the heavenly court
9. Metatron (translation is disputed, may mean "keeper of the watch", "guardian", or "he who sits behind the throne of Heaven"), God's heavenly scribe recording the deeds of all that is

Kinds of Angels

1. Malachim (translation: messengers), general word for angel
2. Seraphim (translation: the burning ones), sing and praise God
3. Ophanim (translation: arbiters), Guardians of the Throne of God
4. Chayot HaKodesh (translation: living beings)

Angels in Christianity

Early Christians inherited Jewish understandings of angels, which in turn may have been partly inherited from the Egyptians. In the early stage, the Christian concept of an angel characterized the angel as a messenger of God.  Angels are creatures of good, spirits of love, and messengers of the savior Jesus Christ. Later came identification of individual angelic messengers:Gabriel, Michael, Raphael, Uriel, and Satan/Lucifer. Then, in the space of little more than two centuries (from the third to the fifth) the image of angels took on definite characteristics both in theology and in art.
By the late fourth century, the Church Fathers agreed that there were different categories of angels, with appropriate missions and activities assigned to them. Some theologians had proposed that Jesus was not divine but on the level of immaterial beings subordinate to the Trinity. The resolution of this Trinitarian dispute included the development of doctrine about angels.
The angels are represented throughout the Christian Bible as a body of spiritual beings intermediate between God and men: "You have made him (man) a little less than the angels..." (Psalms 8:4-5). Some Christians believe that angels are created beings, and use the following passage as evidence: "praise ye Him, all His angels: praise ye Him, all His hosts... for He spoke and they were made. He commanded and they were created..." (Psalms 148:2-5; Colossians 1:16). The Fourth Lateran Council (1215) declared that the angels were created beings. The Council's decree Firmiter credimus(issued against the Albigenses) declared both that angels were created and that men were created after them. The First Vatican Council (1869) repeated this declaration in Dei Filius, the "Dogmatic constitution on the Catholic faith". Of note is that the Bible describes the function of angels as "messengers" and does not indicate when the creation of angels occurred.
Thomas Aquinas (13th century) relates angels to Aristotle's metaphysics in his Summa contra Gentiles, Summa Theologica, and in De substantiis separatis, a treatise on angelology.
Many Christians regard angels as asexual and not belonging to either gender as they interpret Matthew 22:30 in this way. Angels are on the other hand usually described as looking like male human beings. Their names are also masculine. And although angels have greater knowledge than men, they are not omniscient, as Matthew 24:36 points out.

Interaction with angels

The New Testament includes many of interactions and conversations between angels and humans. For instance, three separate cases of angelic interaction deal with the births of John the Baptist and Jesus Christ. In Luke 1:11, an angel appears toZechariah to inform him that he will have a child despite his old age, thus proclaiming the birth of John the Baptist. And in Luke 1:26 the archangel Gabriel visits the Virgin Mary in the Annunciation to foretell the birth of Jesus Christ. Angels then proclaim the birth of Jesus in the Adoration of the shepherds in Luke 2:10. Angels also appear later in the New Testament. In Luke 22:43 an angel comforts Jesus Christduring the Agony in the Garden. In Matthew 28:5 an angel speaks at the empty tomb, following the Resurrection of Jesus and the rolling back of the stone by angels.  Hebrews 13:2 reminds the reader that they may "entertain angels unaware".
Since the completion of the New Testament, the Christian tradition has continued to include a number of reported interactions with angels. For instance, in 1851 Pope Pius IX approved the Chaplet of Saint Michael based on the 1751 private revelationfrom archangel Michael to the Carmelite nun Antonia d'Astonac. And Pope John Paul II emphasized the role of angels in Catholic teachings in his 1986 address titled "Angels Participate In History Of Salvation", in which he suggested that modern mentality should come to see the importance of angels.
As recently as the 20th century, visionaries and mystics have reported interactions with, and indeed dictations from, angels. For instance, the bed-ridden Italian writer and mystic Maria Valtorta wrote The Book of Azariah based on "dictations" that she directly attributed to her guardian angel Azariah, discussing the Roman Missal used for Sunday Mass in 1946 and 1947.