He graduated cum laude from the University of the South with a bachelor of arts in economics. After earning his MBA from Emory University in 1977, Gresham went to law school at the University of Florida where he was a member of the law review and graduated with honors in 1980. In 1981, he was awarded an LL. M. in taxation from New York University. A partner in the law firm of Stoneburner, Berry, Glocker, Purcell & Greenhut, PA, Gresham is a member of Riverside Presbyterian Church and the Jacksonville Downtown Rotary Club. Gresham is married to Katie and they have three children. He joined the Riverside Hospital Foundation Board in 2009.