"Major Barbara" by Bernard Shaw is a three-act play written and premiered in 1905. The story follows Barbara Undershaft, an idealistic Salvation Army officer, whose work helping London's poor is challenged when her estranged father reappears as a wealthy munitions manufacturer. When he donates his "tainted" money to the Salvation Army, Barbara faces a moral crisis. Her father argues that providing steady employment does more good than charity work, forcing Barbara to confront difficult questions about poverty, wealth, and how to truly help society.
Wikipedia page about this book: en.wikipedia.org/wiki/Major_Barbara