On a visit to New Zealand in 1936 to speak at the Ngaruawahia Easter convention he heard four Maori ladies sing 'Po ata rau', or 'Now is the Hour.' Dr Orr was so impressed that he wrote the hymn 'Cleanse me' or 'Lord take my life' on the back of an envelope in the Ngaruawahia Post Office.

He was a brilliant scholar, and held university doctorates. Dr Orr's books on evangelical revival have been published in over one million copies. He was also a US Air Force chaplain and graduated to heavenly honours in 1987.