(Synaxis of the Archangel Gabriel)
Gabriel is the announcer of the Incarnation of the Son of God. He is one of the seven archangels who stand before the Throne of God. He appeared to Zacharias about the birth of the Forerunner. Gabriel said of himself, "I am Gabriel, who stand before God" (St. Luke 1:19). His name Gabriel means "Man - God." The Holy Fathers, in speaking about the Annunciation, interpret that an archangel with such a name was sent to signify who and what He would be like, who must be born of the All-Pure One. Therefore, He will be Man-God, mighty and powerful God. Some of the Fathers understood that this same Gabriel appeared to Joachim and Anna concerning the birth of the Virgin Mary and that Gabriel instructed Moses in the wilderness to write the Book of Genesis.
The Holy Fathers think that Gabriel has pre-eminence in the first and greatest order of heavenly powers, that is, the Seraphic Order, since the Seraphims stand closest to God. He is, therefore, one of the seven Seraphims, closest to God. The names of the seven are MICHAEL, GABRIEL, RAPHAEL, URIEL, SALATHIEL, JEGUDIEL, BARACHIEL. To this number some even add JEREMIEL. Each one has their own particular service and all are equal in honor.
Why did God not send Michael? Because Michael's service is to suppress the enemies of the Faith of God while Gabriel's is the mission of announcing the salvation of mankind.