Most revivalists of the era were flamboyant but Branham was usually calm and spoke quietly, only occasionally raising his voice. His preaching style was described as "halting and simple", and crowds were drawn to his stories of angelic visitation and "constant communication with God". He refused to discuss controversial doctrinal issues during the early years of his campaigns, and issued a policy statement that he would only minister on the "great evangelical truths". He insisted his calling was to bring unity among the different churches he was ministering to and to urge the churches to return to the roots of early Christianity.