In 1643 - during the English Civil War - the Parliament called an assembly of pastors and theologians. The assembly's task was "to propose to Parliament any corrections which might need to be made to the existing structures, worship, and teaching of the church."* Since it met in the Jerusalem Chamber of Westminster Abbey in London, it was known as the Westminster Assembly.
The Westminster Assembly lasted for ten years (1643-53). While the assembly did much more during that decade, its most well-known works are three documents: the Westminster Confession of Faith, the Larger Catechism, and the Shorter Catechism. These documents, known cumulatively as the Westminster Standards, have served as the secondary standards - under the authority of the Bible - of many churches and denominations over the centuries. As a conservative denomination, the ARP Church takes the Westminster Standards very seriously, and seeks to adhere closely to them.
The links at the bottom of this page will take you to the texts of the Westminster Confession and Catechisms.
*Chad Van Dixhoorn, Confessing the Faith: A Reader's Guide to the Westminster Confession of Faith (Carlisle, PA: Banner of Truth, 2014), xvii.