State religion as a model for Christianity was the greatest ill plaguing the medieval Church. The abusive of power by the papacy and the disregard for biblical discipleship were the greatest fractures within the Church that the Reformation sought to fix.
The most successful Reformation model in achieving this was the Anabaptist movement. The least successful is that which took place in England under the monarchy.
By insisting on “free faith” rather than “state religion,” the Anabaptists developed a Church independent of outside control. Having the freedom to model Christianity after the Bible, the Anabaptists rejected the idea that a person becomes a Christian by being born into a “Christian society.” By doing so, biblical discipleship (initiated by adult baptism) could take place in a community of pacifism and spiritual reflection; free from the power structures, impurities and influences of the state.
The English opted for a model of state religion by placing the king/queen as the head of the Church of England. This was problematic for two reasons:
First, it placed the reformation at the mercy of an office that was always changing hands. As various rulers died and others came to power, not all were on board with the Protestant cause.
Second, the fact that people were executed for religious reasons under the monarchy managed to derail the original intent of the Reformation, which was to realign the Church with biblical values and free it from the abuses and impurities of the state.
Anabaptists fought for a church model Evangelicals enjoy today, paving the way for the pursuit of free and authentic biblical discipleship.