 During his education at university, Marino also taught at Epiphany Apostolic College and following his graduation he was the spiritual director at St. Joseph's Seminary in Washington, D.C. from 1968 until 1971, when he became vicar general of the Josephites.From September 12, 1974 until 1988 he was an auxiliary bishop for the Washington archdiocese, the fourth African American ever to hold this position, as well as becoming the secretary of the National Conference of Catholic Bishops in 1985, the first African American to hold that position.In 1987 he organised a trip for a number of African American Catholics to see Pope John Paul II, and during a talk with these men and women, he stated