The Good Man Jesus and the Scoundrel Christ
Jesus is a passionate, charismatic preacher, while Christ is his cynical and introspective twin, with an eye for posterity.
In Pullman's version, Jesus' teachings are recorded by his brother Christ, who rewrites and spins Jesus' words into a story Christ believes will be more future-proof. Christ is manipulated by a mysterious stranger with an unspecified interest in imposing structure through the recognition of Jesus as a spiritual leader.
The book examines the relationship between 'truth' and 'history'; truth being something beyond history, to be teased out of real life events (by well-meaning or manipulative scholars) in order to clarify them.