Merrill grew up in Fargo and attended Oak Grove for four years. While at Oak Grove, Merrill served as Student Body President and received the Quanbeck Athletic Award, which was presented to the best athlete at the school. For many years he held the scoring record in a single basketball game with a total of 41 points. Merrill was a member of Pontoppidan Church, where his dad, Donald Ronning, served as pastor. He graduated from Augsburg College in 1967 and from Luther Seminary in 1972. He served as Oak Grove’s campus pastor from 1972 to 1975. He went on to serve as the youth pastor at First Lutheran and started home mission parishes in Bismark, North Dakota and Eden Prairire, Minnesota. In 1996, Merrill started his own consulting/training company, Ronning Leadership Seminars.