This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The book explains the criticisms of natural theology that have emerged in the Reformed theological tradition. Natural theology in this sense is a way of designating natural knowledge of God', which in the western religious traditions of Judaism, Christianity, and Islam is typically contrasted with the knowledge of God derived from sacred scripture or divine revelation. Two important conceptual distinctions emerge from the historical discussion that will be essential to the subsequent analysis of Reformed objections to natural theology. First, there is a distinction between natural theology as natural knowledge of God and natural theology as rational proofs or arguments for the existence and nature of God. Secondly, while there is consensus in the Reformed tradition on the propriety of the project of developing theistic arguments, there is a diversity of views on the function of theistic arguments.