This is a prophetic word from Isaiah foretelling the coming Messiah, Jesus Christ.
Isaiah 9:6-7 - For unto us a child is born, to us a son is given, and the government will be on his shoulders. And he will be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace. Of the greatness of his government and peace there will be no end. He will reign on David’s throne and over his kingdom, establishing and upholding it with justice and righteousness from that time on and forever. The zeal of the LORD Almighty will accomplish this.
What does “unto to us a Child is born, and unto us a Son is given” mean?
I think that it is a reminder that Jesus is for everyone and He is a gift from God. Salvation is available for all who call on the Name of the Lord.
If you declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved. - Romans 10:9
If we accept this gift of salvation then we too are reborn, and we are given to the Son. To give Him honor and glory all the days of our lives should be our main focus.