Before His birth, God used angels to divinely establish and authenticate who and what Jesus was.
In fulfillment of God's promise to faithful king David some 900 years ago (2 Sam 7:12-16),
the angel Gabriel told Mary that her Son was the King from the line of David who would reign forever (Luke 1:26-33).
In fulfillment of God's promise to faithless king Ahaz some 600 years ago (Isa 7:14),
the angel told Joseph that his Son was the Immanuel (Hebrew: God with us) of virgin birth, which was the miraculous sign for those who
doubted God's reality and salvation (Matt 1:19-25). As instructed, Joseph and Mary
named their Son Jesus which, in Hebrew, meant "Yahweh is salvation."
She will bear a Son; and you shall call His name Jesus (Yahweh is salvation), for He will save His people from
their sins. (Matt 1:21)
In speaking of His preeminence and purpose, the apostle John placed an emphasis on the name of Jesus:
But as many as received Him, to them He gave the right to become children of God, even to those who believe
in His name, (John 1:12)
Jesus' divinely bestowed name emphasized His purpose, Yahweh is salvation, and was exalted above all other names:
Being found in appearance as a man, He humbled Himself by becoming obedient to the point of death, even death
on a cross. For this reason also, God highly exalted Him, and bestowed on Him the name which is above every name, so that at the
name of Jesus every knee will bow, of those who are in heaven and on earth and under the earth, and that every tongue will confess that
Jesus Christ is Lord, to the glory of God the Father. (Phil 2:8-11)
To learn more, see:
Messianic prophecies of Jesus' name, birth, and origin
What's in a name? A look at genealogies…