The Way of the Light was a book written by Lothair Mantelar  during the War of the Hundred Years. In it, he outlined a humble, simple life dedicated to serving the Light that he believed all should follow. He also asserted that touching the True Source was for the Creator alone, and that those humans who wielded it (namely Aes Sedai) were Darkfriends. The book became the basis for the ideology of the Children of the Light.
Shortly after Morgase and Galad are reunited, and before Morgase officiates at Perrin Aybara's trial, the two have a quiet and private conversation where Galad sets the record straight. He claims that according to The Way of the Light, not all women who wield the One Power are inherently evil, stating that such is a mistaken tradition of the Children. Galad continues by saying that the book really says that temptation to wield the One Power can corrupt. He further elaborates the point by concluding that the schemes and selfish plots of the White Tower Aes Sedai have blinded them, and that he and the Children will fight alongside them, The Dragon Reborn and even Perrin Aybara, the latter whom he believes may possibly be a murderer of Whitecloaks and a Darkfriend. The struggle against the Shadow outweighs all other concerns.