[2] In 1906, Roper commenced his training for the priesthood at St Patrick's Seminary in Manly, Sydney, New South Wales, where he was one of their most brilliant students.
[2][3][4] On 30 November 1911 Roper was ordained a Roman Catholic priest at St Mary's Cathedral in Sydney and commenced his service in the Diocese of Ballarat, Victoria.
[1][4] On 13 July 1938 he was appointed as Bishop of Toowoomba in Queensland, being consecrated on 18 October 1938 at St Patrick's Cathedral in Ballarat in a service led by the Archbishop of Melbourne, Daniel Mannix.
He was then enthroned at St Patrick's Cathedral in Toowoomba on 20 November 1938 in a service led by Archbishop of Brisbane, James Duhig.
[2] In October 1952, Roper announced his retirement due to his failing health not being able to cope with the demands of his role, but continued in an administrative capacity until he was replaced.