Have you ever noticed that when God changes someone's circumstances or gives them a new direction He changes their name? It happened to Abram who became Abraham after God promised him a son and a blessing. It happened to Sarai when she too was blessed with this promised son and she became Sarah. It happened to Jacob after he wrestled with God he was given a blessing and a new name, Israel. And it happened to Joseph after he was rescued from the prisons of Egypt the Pharaoh gave him the Egyptian name Zaphenath-Paneah and put him in charge of preparations for the looming famine.
It also happened in the New Testament. Saul, the Jewish zealot became Paul the apostle some time after his conversion to Christianity. Time and time again when God changes someone's circumstances or gives them a new direction He changes their name.
I was given the name David by my parents when I was born, but when I was baptized at the age of nine my name was changed. My circumstance was changed, I was given a new direction and God changed my name. God calls me by my new name, Christian, or like-Christ.