 His first assignment was serving as the associate pastor of the Cathedral of the Risen Christ, and he also served as a teacher at Pius X High School in Lincoln.From 1982 to 1985, Jackels was assigned to be the associate pastor of St. Thomas Aquinas Parish on the campus of the University of Nebraska, and in addition to his teaching duties at Pius X High School, he also served as the assistant vocations director for the diocese during this period.In 1985, Jackels embarked on doctoral studies at the Pontifical University of St. Thomas Aquinas ("Angelicum") in Rome, earning his doctorate in Sacred Theology in 1989.