The Three Forms of Unity is a collective name for the Belgic Confession, the Canons of Dort, and the Heidelberg Catechism, which reflect the doctrinal concerns of continental Calvinism and are accepted as official statements of doctrine by many Calvinist churches.
From 1618 to 1619, the Dutch government on behalf of the Dutch Reformed Church, called and convened the Synod of Dort. Dutch delegates, along with twenty-seven Calvinist representatives from eight other countries, met at this Synod of Dort, where they collectively summarized their views in what was called the "Canons of Dort".[1]
This same Synod then added these Canons to two other documents, both of which were in common use by the Dutch Church at the time: the Heidelberg Catechism (1563) and the Belgic Confession (1561).[1]
In so doing, the Synod sought:
The different documents each serve different purposes.
Some Reformed denominations have included the Westminster Confession to their confessional standards. These include the Christian Reformed Church of Australia[2] and the Reformed Churches of New Zealand[3]