Hay grew up in Minnesota. He graduated from the Columbia Theological Seminary in Decatur, Georgia in 1966 and began his career as pastor of Edgewood Presbyterian Church. He and Frank Barker co-founded the Birmingham Theological Seminary at Edgewood in 1972.
He split with the mainline congregation and joined Barker's more conservative Presbyterian Church in America. He announced from the pulpit his intention to launch a new church in 1978, surprising even his wife, Cyndie. The new church met at Samford University's Reid Chapel until establishing their own campus on Old Montgomery Highway nearby.
Hay informed his church of his desire to retire in 2008, but no successor was named until 2011, when Bill Boyd was called to Covenant Presbyterian. He remains a member of the church and attends with his wife, three children, and seven grandchildren.
- Garrison, Greg (October 1, 2011) "After 45 years as a pastor in Homewood, Bill Hay retires." Birmingham News