On completion of his theological course at Assembly’s College, Belfast, he was licensed by the Ballymena Presbytery acting as assistant at St. Enoch’s Church, Belfast. His first pastoral charge was Hill Street, Lurgan where he was ordained on 17th April 1901. He resigned from the pastorate on receiving a call from Malone congregation in March 1912. For more than seven years he ministered at Malone until his appointment in June 1919 as Professor of Systematic Theology in the Assembly’s College, Belfast. Throughout his career he obtained a degree of Bachelor of Divinity, from the University of London in 1901, and in 1931 he received from St. Andrew’s University, Scotland, a degree of Doctor of Divinity.
In 1944 he resigned from the Chair of Systematic Theology and was succeeded by his son, the Rev. J.L. M. Haire, M.A., B.D., formerly of Maghera. Professor Haire took a great interest in the work of Foreign Missions, and from 1920 until 1937 he acted as joint convener.
He died on 12th October 1959 after a long illness and is buried in Drumbeg Churchyard.