He was the founder and host of the "Voice of Calvary" radio and television ministries, conference speaker, author, church planter, and father of pastor John F. MacArthur.

Subsequently, while his son John was an undergraduate at Los Angeles Pacific College (defunct), a four-year microcollege, MacArthur was awarded an honorary doctorate of literature from the same school.

You don't grow up a pastor's son without hearing a few thousand sermons - some more than once...[but] what I found as I watched - and what has most profoundly influenced me - was that my father's life rang true...in a word, what he taught me was the value of integrity.

Later, he served as director of evangelism for the Charles F. Fuller Foundation and as a field evangelist for the Moody Bible Institute of Chicago.

[3][8] While still pastoring in Southern California, he and Dr. J. Edwin Orr founded an outreach ministry to people in the film and television industry in the early 1940s"[9] where Roy Rogers and Dale Evans came to Christ under his preaching in 1948, and eventually, lifelong friends.