Original sentence: A Christian () is a person who adheres to Christianity, an Abrahamic, monotheistic religion based on the life and teachings of Jesus of Nazareth, who they believe is the Messiah (the Christ in Greek-derived terminology) prophesied in the Old Testament/Hebrew Bible, and the son of God
Edited sentence: A Christian () is a person who adheres to Christianity, an Abrahamic, monotheistic religion based on the life and teachings of Jesus of Nazareth, who is the Messiah (the Christ in Greek-derived terminology) prophesied in the Old Testament/Hebrew Bible, and the son of God