How should the American church tackle domestic poverty, and how should US faith-based aid organizations approach the change process in developing countries? These questions about aspects of the church in mission are best answered in light of a wider historical debate about the relationship between church and state. In this article, I explore the history of this relationship and argue that the radical separation of church and state favored by conservative evangelicals in the United States, harms the disadvantaged both domestically and abroad. Just as governments should not abrogate their responsibility to the poor, Christian institutions should not shrink from their God-given task of holding secular, political authorities to account. How should the American church tackle domestic poverty, and how should US faith-based aid organizations approach the change process in developing countries? These questions about aspects of the church in mission are best answered in light of a wider historical debate about the relationship between church and state. In this article, I explore the history of this relationship and argue that the radical separation of church and state favored by conservative evangelicals in the United States, harms the disadvantaged both domestically and abroad. Just as governments should not abrogate their responsibility to the poor, Christian institutions should not shrink from their God-given task of holding secular, political authorities to account.