Why was Jesus named Jesus, and not Emmanuel?

The Messiah goes by many other names in scripture, including Immanuel.  The name given to the Christ child came directly from the Father Himself, as revealed by the angel:

Luke 1:30 The angel said to her, “Do not be afraid, Mary; for you have found favor with God.
Luke 1:31 “And behold, you will conceive in your womb and bear a son, and you shall name Him Jesus.

The name Jesus is actually Yeshua in Hebrew, which is also translated Joshua. The name means “the Lord is salvation,” so clearly the Father wanted His Son to bear a name that announced His purpose.  

This is the earthly name for our Messiah, but before He was revealed to the world, the scripture speaks of Him using other names. Collectively, there are over 200 different names or titles given to the Messiah in scripture. Taken together, these names describe the character and work of the Messiah in the plan of God. 
The first name the Lord gave Himself is found in Exodus:

Ex. 3:14 God said to Moses, “I AM WHO I AM”; and He said, “Thus you shall say to the sons of Israel, ‘I AM has sent me to you.’”

Later in John’s Gospel, Jesus continued to use this name in a subtle way, when He responded to the Pharisees this way:

John 8:58 Jesus said to them, “Truly, truly, I say to you, before Abraham was born, I am.”

In His return to earth, the Lord will assume yet another name, as Jesus says in Revelation 3:

Rev. 3:12 ‘He who overcomes, I will make him a pillar in the temple of My God, and he will not go out from it anymore; and I will write on him the name of My God, and the name of the city of My God, the new Jerusalem, which comes down out of heaven from My God, and My new name.

So even the name Jesus is not the Lord's final name. His new name is described this way in Revelation 19:

Rev. 19:16 And on His robe and on His thigh He has a name written, “KING OF KINGS, AND LORD OF LORDS.”

So the question of what is the Messiah’s name is different than asking a human being for a name. Since there is no one like the Lord, He doesn’t bear a name to distinguish Himself from another. The only reason the Lord adopts a name is to describe Himself to His Creation. Therefore, the Lord names Himself as a means of describing Himself to mankind using multiple names. 

Scripture quotations taken from the (NASB®) New American Standard Bible®, Copyright © 1995, 2020 by The Lockman Foundation. Used by permission. All rights reserved. www.lockman.org