Rev. John G. Block was ordained to the Sacred Priesthood on December 18, 1964 for the Diocese of Miami Florida at the Church of Christ the King, Rome, Italy. He received a Licentiate in Sacred Theology in June 1964 and a Doctorate in Sacred Theology in June 1970 from the Gregorian University, Rome, Italy.
He taught Theology at St Vincent De Paul Regional Seminary, Boynton Beach, Florida from July 1, 1971 to July 1, 1980 at which time he was appointed Pastor of St Mark Parish, Boynton Beach. He became a member of the Diocese of Palm Beach, Florida upon its establishment on October 24, 1984.
He was Pastor of St Mark Parish until August 1, 1997 at which time he moved to St Bonaventure Parish. He retired from the Diocese of Palm Beach on August 1, 2001.