He has served as bishop of the Diocese of Springfield-Cape Girardeau since 2008. In 1985, he left his occupation as an engineer to pursue a call to the priesthood. He obtained his Master of Divinity degree from St. Meinrad College and School of Theology and was ordained a priest of the Diocese of Knoxville, Tennessee on June 9, 1990, at Holy Ghost Church in Knoxville, his home parish. He obtained a Licentiate in Canon Law in 1996 from the Catholic University of America in Washington, D.C.
Bishop Johnston has had the privilege to visit the Vatican on several occasions. He met Pope John Paul II when he visited Rome as a seminarian and again as a priest in 1996. Then, as a new bishop in September 2008, he met with the Holy Father, Pope Benedict XVI. His most recent visit to the Vatican was in March 2012 for his Ad Limina Apostolorum visit. The Ad Limina Apostolorum visit, which translates “to the threshold of the apostles,” is a requirement for every bishop from around the world to go to the Vatican for meetings with the various dicasteries of the Holy See as well as the Pope.
Not only are these visits a time for bishops to meet personally with the Holy Father and update him on the affairs of his diocese, it is also a time of pilgrimage to the tombs of Saint Peter and Saint Paul. Bishop Johnston anticipates his next Ad Limina visit in 2017 when he will have the opportunity to meet with Pope Francis.