Angel Mythology (Angelology)

Gabriel (Archangel)

According to Jewish mythology, in the Garden of Eden there is a tree of life or the "tree of souls" that blossoms and produces new souls, which fall into the Guf, the Treasury of Souls. Gabriel reaches into the treasury and takes out the first soul that comes into his hand. Then Lailah, the Angel of Conception, watches over the embryo until it is born.

Intertestamental literature
The intertestamental period (roughly 200 BCE – 50 CE) produced a wealth of literature, much of it having an apocalyptic orientation. The names and ranks of angels and devils were greatly expanded, and each had particular duties and status before God.

In 1 Enoch 9:1–3, Gabriel, along with Michael, Uriel and Suriel, "saw much blood being shed upon the earth" (9:1) and heard the souls of men cry, "Bring our cause before the Most High." (9:3) In 1 Enoch 10:1, the reply came from "the Most High, the Holy and Great One" who sent forth agents, including Gabriel—

And the Lord said to Gabriel: "'Proceed against the bastards and the reprobates, and against the children of fornication: and destroy [the children of fornication and] the children of the Watchers from amongst men [and cause them to go forth]: send them one against the other that they may destroy each other in battle: for length of days shall they not have." —1 Enoch 10:9

Gabriel is fifth of the five angels who keep watch: "Gabriel, one of the holy angels, who is over Paradise and the serpents and the Cherubim." (1 Enoch 20:7)

When Enoch asked who the four figures were that he had seen: "And he said to me: 'This first is Michael, the merciful and long-suffering: and the second, who is set over all the diseases and all the wounds of the children of men, is Raphael: and the third, who is set over all the powers, is Gabriel: and the fourth, who is set over the repentance unto hope of those who inherit eternal life, is named Phanuel.' And these are the four angels of the Lord of Spirits and the four voices I heard in those days." (Enoch 40:9)

Christianity
Old Testament
The angel Gabriel is mentioned in Daniel 8:16-26 and 9:20-27. Gabriel, "one who looked like a man," (Dan. 8:15 NIV) interprets Daniel's visions, and Daniel "was terrified and fell prostrate" (Dan. 8:17 NIV). Gabriel speaks to Daniel while he is in a deep sleep, and Daniel is tired and sick for days after being with Gabriel (Dan. 8:27 NIV). In Chapter 9, verse 20-21, Gabriel again appears to Daniel as he was praying, giving him insight and understanding in an answer to prayer (Dan. 9:20-27 NIV).

New Testament
First, concerning John the Baptist, an angel appeared to his father Zacharias, a priest of the course of Abia, (Luke 1:5-7) whose barren wife Elisabeth was of the daughters of Aaron, while he ministered in the temple:

Luke 1:10 And the whole multitude of the people were praying without at the time of incense.
11 And there appeared unto him an angel of the Lord standing on the right side of the altar of incense.
12 And when Zacharias saw him, he was troubled, and fear fell upon him.
13 But the angel said unto him, Fear not, Zacharias: for thy prayer is heard; and thy wife Elisabeth shall bear thee a son, and thou shalt call his name John.
14 And thou shalt have joy and gladness; and many shall rejoice at his birth.
15 For he shall be great in the sight of the Lord, and shall drink neither wine nor strong drink; and he shall be filled with the Holy Ghost, even from his mother’s womb.
16 And many of the children of Israel shall he turn to the Lord their God.
17 And he shall go before him in the spirit and power of Elias, to turn the hearts of the fathers to the children, and the disobedient to the wisdom of the just; to make ready a people prepared for the Lord.
18 And Zacharias said unto the angel, Whereby shall I know this? for I am an old man, and my wife well stricken in years.
19 And the angel answering said unto him, I am Gabriel, that stand in the presence of God; and am sent to speak unto thee, and to shew thee these glad tidings.
20 And, behold, thou shalt be dumb, and not able to speak, until the day that these things shall be performed, because thou believest not my words, which shall be fulfilled in their season.
(Luke 1:10-20 KJV) (other versions: Luke 1:1-25)