Thornbury was ordained in 1996 at the First Baptist Church (
Southern Baptist) of
Clarksville, Indiana. Most of his career has been spent in higher education at
Union University in
Jackson, Tennessee. In 1998, David Dockery of Union recruited him to teach philosophy, after acquiring permission from Henry for the name. In 2006, Thornbury became the founding dean of the Union School of Theology and Missions at Union University, where he initiated several new graduate programs, including a doctoral program in
Singapore. He also supervised Union's Spiritual Life division as vice president, and led the university's chapel, and campus discipleship programs. Thornbury accepted the position of vice president at the
New York Academy of Art and resigned as chancellor of King's College in 2018. In 2023, Thornbury joined Silver Art as its executive director, following his tenure as vice president of the New York Academy of Art. He was introduced to the organization through a conversation with the Silverstein Family at a dinner event and subsequently accepted the role. Silver Art Projects is a nonprofit residency program, founded in 2019 by Cory Silverstein and Joshua Pulman, and based at the
World Trade Center and offers artists free studio space and stipends. He has been active in the arts, and has spoken at exhibitions of the work of
Carl Perkins,
Larry Norman, and
Daniel Johnston. He has also served as a visiting professor at Ansgar Teologiske Høgskole in
Norway. In recent years, he has critiqued evangelical Christianity and distanced himself from its ideas and institutions. ==The King's College==