A Presbyterian Minister of Word and Sacrament since 1964, Warner's career has combined the roles of pastor and scholar in his leadership of outstanding congregations in Indiana and Texas through significant transformation. At regional and denominational levels, he has served his church in areas of peacemaking, fund-raising, education, mission, and judicial affairs. He has been a commissioner to two national General Assemblies where he chaired committees on the Brief Statement of Faith (1989) and Bills and Overtures (2003).

Within the Fort Worth community Warner has been president of the board of the Parenting Center and founding president of an AIDS funding agency. He served on the board of the Presbyterian Night Shelter, United Way, and Planned Parenthood of North Texas. He is a member of Leadership Fort Worth.

As a scholar his area of continuing interest is the reception of biblical interpretations that challenge conventional ideas. He has contributed articles to the Journal of Presbyterian History, and his essays have appeared internationally in a Festschrift and a centennial collection. He continues his research and writing in the Book of Psalms and 1 and 2 Samuel.

Warner maintains an active life in retirement with his involvement at Brite Divinity School as Director of Presbyterian Studies and Adjunct Faculty member and as a member of the Steering Committee for Building a Brite Future. He is a Parish Associate at St. Stephen Presbyterian Church where he serves as Theologian-in-Residence. He accepts invitations for preaching and teaching. He and his wife, Mary, have two children.