Protestantism in Germany is currently experiencing a tremendous pluralization and increase in the segment of independent churches. There is a striking disparity between the Protestant regional churches and the free churches. While the former are privileged with a monopoly position in public discourse, the latter are perceived at best as a marginal phenomenon. This problematic situation is exacerbated intersectionally in the case of migration congregations due to ethnic differences and is to be regarded as a serious theological problem. The chapter poses the question of how Protestant regional churches and Protestant free churches can find a way to interdenominational cooperation. The chapter documents an empirical, ecclesiastical, and theological investigation of Protestantism as part of German church culture.