Jesus is fully God. When He came to earth and was born of the Virgin Mary, Jesus also became a human being, a person like you. So Jesus is both God and Man. As God, Jesus has always existed - he was not created when he was born. Instead, he willingly chose to take on a human body.
Before anything else existed, there was God's Son. He was the Word, and He was with God. He has always been alive and is Himself God. (John 1:1-2)
John 1:14; 14:9; Colossians 1:15-18