Paul Brown Long was born in West Virginia on August 7, 1923, to Mr. and Mrs. George W. Long, the youngest of three children. While his sister attended Wheaton College, he joined her so he could attend Wheaton Academy to be able to participate in sports. In 1939, while a student at the Academy, he was converted. In 1942, he graduated from Wheaton Academy and entered Wheaton College. To raise money to attend Wheaton College, he convinced the Physical Education department to add a horsemanship program as to their curriculum and Long taught in this new program before and after his service in the army.

In 1942, Long enlisted in the army and was assigned as an instructor in cargo packing, horsemanship, light weapons, and physical education. He served in Burma and China during World War II. In China, he served under Chinese officers in the Sixth Army, having responsibility for the care and movement of their horses and mules, as they followed after a rapidly retreating Japanese army. He left China in 1946 to return to college, but because of the ill-health of his father, along with his brother George, had to switch off between farming and college, each taking a year in turn.

As early as 1940, Long felt called to go to Africa as a missionary. A period of struggle followed the call until he finally surrendered his life to God. After graduating from Wheaton College in 1950, under the urging of his brother, Long attended Columbia Seminary in Georgia, from which he received a Th.B. degree in 1953. At Wheaton, Long had met and married Merry Dalton, a Canadian nurse. He and his wife applied to the Southern Presbyterian Mission Board, which assigned them to what was then the Belgian Congo. In the Congo, Long became director of regional schools, did evangelistic work, and even cared for the mission's one hundred fifty head of cattle and Merry worked as part of the medical team. During a furlough, Long earned a Th.M. in 1958 from the Louisville Presbyterian Seminary. The Longs were forced to leave the Congo during the 1960 rebellion.

After a year of graduate work at Union Theological Seminary in Richmond, VA, and another year as pastor of a Virginia church, Long heard about the opening up to missionary work of the interior of Brazil because of the construction of the new capitol, Brasilia. He asked for and was assigned pioneer church planting work in an eight hundred mile stretch along the Brasilia-Belem highway in North Goias, Brazil. After eleven years in that area, he was assigned to an area on the Trans-Amazonian High. After experiencing heart problems, Long returned to the United States to complete work on a Ph.D. degree at Fuller Seminary and from there became a professor in the missions program at the Reformed Theological Seminary in Jackson, MS.

In 1986 Long published a book titled The Man in the Leather Hat and Other Stories, which was inspired by his work in Brazil. The Longs had five children, all of whom graduated from Wheaton College: Paul Brown II (BA, '72), Mary Elizabeth (BA '74), Virginia Ann (BA '76), Stephen Dalton (BA '79), and Charles Alexander (BA '82).

Paul Long passed away on January 29, 2018.