The Plymouth Brethren movement was an independent work of the Holy Spirit, which is apparent from the fact that, in A. D. 1812 and 1820, letters were passed between a company of believers in Great Britain. The Brethren believe that they represent the true church established on the day of Pentecost. The two guiding principles of the movement were to be the breaking of bread every Lord's Day, and ministry based upon the call of Christ rather than the ordination of men. They follow and obey the Scripture, refusing to follow human tradition and creed. Others call them Brethren, but they prefer to be called Christians.