The playwright who did the book for Porgy and Bess was Debose Heyward. (Not sure of the spelling).

ira and George had a skeptical view of religion. They were motivated to give "the Devil his due"...so to speak. E.Y. Harburg wrote a similar song called "Ain't That the Truth" for Sportin' Life's female counterpart in the movie "Cabin In the Sky". "Truth" was cut from the movie for being too controversial.

Frank