An officer of The Salvation Army, Major Barbara Undershaft, becomes disillusioned when her Christian denomination accepts money from an armaments manufacturer (her father) and a whisky distiller. She eventually decides that bringing a message of salvation to people who have plenty will be more fulfilling and genuine than converting the starving in return for bread.
Although Barbara initially regards the Salvation Army's acceptance of Undershaft's money as hypocrisy, Shaw did not intend that it should be thought so by the audience. Shaw wrote a preface for the play's publication, in which he derided the idea that charities should only take money from "morally pure" sources. He points out that donations can always be used for good, whatever their provenance, and he quotes a Salvation Army officer, "they would take money from the devil himself and be only too glad to get it out of his hands and into God's".