The response of Melbourne's churches to war has varied according to their understanding of their relationship to the state, the values and numbers of their adherents, the nature of the clergy, and the issues raised by each war. Until the 1950s the distinctive character of religion in Melbourne was shaped by the Irish nationalism of Catholic Archbishop Daniel Mannix and the wowserism of the nonconformist Protestant churches. Yet minority groups within Melbourne's churches, frequently led by Quakers, have been prominent in anti-war and peace movements since the beginning of World War I.
The oppositional voice was faint during World War I when the majority of clergy, preaching the need for national regeneration and moral renewal, supported conscription and argued for restriction of alcohol consumption, entertainment and sport. Those like Leyton Richards, Unitarian Frederick Sinclaire, Australian Church founder, Charles Strong, and later Daniel Mannix, who opposed the war and/or conscription, or raised the theological concept of a just war, suffered ostracism and obloquy. Mannix's titular leadership of the anti-conscription campaign in 1917 provoked unprecedented levels of sectarianism that militated against the possibility of ecumenism in Melbourne for more than half a century.
During World War II the churches focused on the social issues. Protestants, led by Methodist minister C. Irving Benson, defended the Sabbath and the existing liquor licensing laws against those who argued for liberalisation in the interests of troop morale, while Mannix, long an admirer of Fascist Italy's anti-communist stance, used his influence to limit the number of Italians interned. Jewish congregations, for their part, took an active role in the Victorian International Refugee Emergency Council and the Australian Open Door Council, preparatory to assisting the settlement of displaced persons in the postwar years.
The patriotic consensus was shattered during the Cold War. While Catholics and Protestants found common cause in warning their congregations at rallies and crusades against the dangers of communism, there were dissenting voices. Australia's involvement in the Vietnam War affected all the churches, with the concept of a just war central to their debates. Although there remained a strong core of conservative pro-war sentiment in all the churches, the anti-war forces gradually became stronger. Influenced by the liberalism of Vatican II, Melbourne's Pax Christi represented the voice of young priests and radical lay Catholics such as Max Charlesworth. Quakers inspired the non-violent protests of Save Our Sons, and Christian pacifists took a prominent part in Melbourne's large Vietnam Moratorium. Although these ecumenical alliances have been apparent in the oppositional stance of many mainstream clergy to subsequent wars, the decline in church attendance has diminished their impact on public debate.