Anabaptists required that baptismal candidates be able to make a confession of faith that was freely chosen, and so rejected baptism of infants. ... Anabaptists were persecuted largely because of their interpretation of scripture that put them at odds with official state church interpretations and government.

What were the Anabaptists persecuted for?

Most Anabaptists were pacifists who opposed war and the use of coercive measures to maintain the social order; they also refused to swear oaths, including those to civil authorities. For their teachings regarding baptism and for the apparent danger they posed to the political order, they were ubiquitously persecuted.

Why were the Anabaptists considered radical?

Anabaptists were considered radical because some of their subdivisions believed in radical social change, such as the end of private property or violence in order to bring about the Day of Judgement.