An Etymological Dictionary of the German Language/Annotated/Glaube
Glaube, masculine, ‘belief, credit, creed,’ from the equivalent Middle High German geloube (by syncope gloube), Old High German giloubo, masculine; an abstract common to West Teutonic; corresponding to Old Saxon gilôƀo, Dutch geloof, Anglo-Saxon geleáfa (English belief). With this glauben is connected earlier (in Luther) gleuben, from the equivalent Middle High German gelouben (glöuben), Old High German gilouben, gilouppen; compare Old Saxon gilôbian, Dutch gelooven, Anglo-Saxon gelŷfan, English to believe, Gothic galaubjan, ‘to believe.’ The primary meaning is ‘to approve.’ To the same root lub belong erlauben, lieb, loben, and Urlaub.