Final answer:
The movement for unity among Christian Churches is known as the ecumenical movement, characterized by efforts to bring together various denominations to achieve common understanding and cooperation.
Step-by-step explanation:
The movement for unity among the Christian Churches is known as the ecumenical movement. This movement aims to bring together the various Christian denominations and work towards a common understanding and cooperation.
Historical instances of efforts towards unity include ecumenical councils, which gathered Christian bishops to settle matters of doctrine within the Church. The word "ecumenical" derives from the Greek oikoumene, meaning the entire inhabited world, signifying the universal nature of these gatherings and their decisions.
Throughout history, such as during the Second Great Awakening, different movements like the Restoration Movement also sought to unify Christians and ‘restore’ the Church to its original form as described in the New Testament.
While movements like Unitarianism emerged during the same period, focusing on human reason and the inherent goodness of humankind, it does not represent the unity movement among all Christian Churches. The Restoration Movement is a better example of this effort within the context of American religious history.
In this vein, Christian unity seeks to bridge the divisions that have historically separated denominations, such as those resulting from the Great Schism of 1054, which split Eastern Orthodox Christians and Roman Catholics.