The Baptist movement was radical in its nature, but the baptismal question was secondary in its importance. The movement involved the entire reconstruction of the State Church and of much of the social order. It was nothing less than revolutionary.
The Reformers aimed to reform the Roman Catholic Church by the Bible; the Baptists went directly to the apostolic age and accepted the Bible alone as their rule of faith and practice.
The Reformers founded a popular State Church, including all citizens and their families; the Baptists insisted on the voluntary system and selected congregations of baptized believers, separated from the world and the State (Schaff, History of the Christian Church, VII. 72).
They preached repentance and faith, they organized congregations, and exercised rigorous discipline. They were earnest and zealous, self-denying and heroic. They were orthodox in the articles of the Christian faith.
John Christian, A History of the Baptists, vol. 1