This book records the history of how the collaboration of the Catholic and Protestant churches contributed to social changes in Hong Kong, a former British colony. It begins immediately after the conclusion of the Second Vatican Council during the turbulent period of the Cold War in the Asian context from 1966 to 1980. It particularly focuses on their services in education and social changes for the local Chinese and refugees from communist China and Vietnam. It also discusses how the Catholic diocese in Hong Kong attempted to follow the ecumenical guidelines of Vatican II to resolve certain doctrinal issues with the Protestants in the Chinese Christian context. This further enhanced their relationship and collaboration for the welfare of the colonial society. This book also demonstrates the collaborations between Western missionaries and Chinese Christians of both the Catholic and Protestant churches for the good of the society, which reveals that Hong Kong was always an open global society welcoming Western and Chinese cultures rather than limiting itself to nationalism and sinicisation.