Luke is the only Gospel writer to record Gabriel’s first announcement of Jesus’ upcoming birth (1:26-38):
And in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth, To a virgin espoused to a man whose name was Joseph, of the house of David; and the virgin’s name was Mary. And the angel came in unto her, and said, Hail, thou that art highly favoured, the Lord is with thee: blessed art thou among women. And when she saw him, she was troubled at his saying, and cast in her mind what manner of salutation this should be. And the angel said unto her, Fear not, Mary: for thou hast found favour with God. And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS. He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end. Then said Mary unto the angel, How shall this be, seeing I know not a man? And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God. And, behold, thy cousin Elisabeth, she hath also conceived a son in her old age: and this is the sixth month with her, who was called barren. For with God nothing shall be impossible. And Mary said, Behold the handmaid of the Lord; be it unto me according to thy word. And the angel departed from her.
Gabriel declared to Mary that she would give the name Jesus to her miraculously conceived Son (1:31). She was also told that the Lord God would give Him the throne that He would one day have in His eternal kingdom (1:32).
Hearing these statements, a perplexed Mary inquired how she as a virgin would conceive and bear a Son (1:34). Gabriel answered that these miraculous events would be the result of the Holy Spirit’s coming upon her and of the power of the Highest that would overshadow her (1:35).
Because of the work of both the Lord God and the Holy Spirit, Jesus would therefore be called “the Son of God” (1:35). This statement along with several other aspects of all the statements that Gabriel made to Mary does show that her Son would Himself be God.
These angelic declarations, however, do more than announce the fact that Jesus would be God Himself. Among other things, the references to Jesus, the Lord God, and the Holy Ghost in Gabriel’s statements to Mary show that she was given a Trinitarian announcement of the birth of her divine Son.
Mary’s ready acceptance of this marvelous announcement (1:38) displays that she believed the Trinitarian message that she received from Gabriel. Like Mary, anyone after her who would receive Jesus aright must accept not just that He is God Himself but also the Trinitarian truths (cf. Matt. 1:20; Lk. 1:45; 2:26; 30-31) that a right proclamation of the meaning of His name communicates.