Thomas Obadiah Chisholm was born on 29 July 1866 in a log cabin in Franklin, Kentucky. He had only a rural elementary education, taught school briefly, and was ordained a Methodist Episcopal minister in 1903 — but chronic ill health forced him to leave the pastorate within a year, and he supported his family for the next 50 years as an insurance agent in Vineland, New Jersey.
Chisholm wrote hymn texts as a private discipline and mailed them to musical friends. In 1923 he sent 'Great Is Thy Faithfulness' — three stanzas and a chorus meditating on Lamentations 3:22–23 ("His mercies are new every morning") — to William M. Runyan, an editor at the Hope Publishing Company in Kansas.
Runyan set the text to a slow, chorale-like tune and included it in his 1923 Songs of Salvation and Service. It circulated quietly for two decades until it was adopted as the unofficial hymn of the Moody Bible Institute chapel in the mid-1930s, and reached global circulation when the Billy Graham crusade adopted it in 1945.
Chisholm published over 1,200 poems in his lifetime — 800 of them set to music — and continued mailing texts to publishers until his death at the Methodist Home for the Aged in Ocean Grove, New Jersey, on 29 February 1960. Asked late in life for the story behind 'Great Is Thy Faithfulness', he replied simply that the hymn had no dramatic story: he had spent 60 years watching God's mercies renew each morning.