In the Light of Truth: The Grail Message is a book written by Oskar Ernst Bernhardt (1875–1941), the leader of the Grail Movement, a millenarian new religious movement, and first published in 1926 under the pen name Abd-ru-shin. An expanded, complete edition was published by the author under the name of Abdruschin in 1931, entitled Im Lichte der Wahrheit (In the Light of the Truth).