The Serenity Prayer belongs to Reinhold Niebuhr, but establishing that took a scholarly detective story. Niebuhr, the American Protestant theologian, used the prayer in preaching from around the 1930s and 1940s, allowed it to be printed, and regarded it as his own, while remarking that it may have been spooking around for years. His daughter Elisabeth Sifton's 2003 book placed its composition in a 1943 sermon at Heath, Massachusetts.
In 2008 the quotation scholar Fred Shapiro published newspaper and archive findings showing versions of the prayer in print through the 1930s, sometimes unattributed and sometimes credited to others, and suggested Niebuhr might have absorbed rather than authored it, a challenge that drew wide attention and a firm response from Sifton.
The story then turned again. Continuing database searches surfaced earlier printings that did credit Niebuhr, including one from 1937 describing the prayer as his, and in a 2014 article in The Chronicle of Higher Education Shapiro reported that the new evidence had changed his mind, concluding that Niebuhr most likely did originate the prayer. That is where scholarship rests, an attested attribution with an honest history of doubt attached, and the episode is itself instructive, a model case of how a famous text's origin can be tested rather than assumed.