Religion and Democratization is a comparative study of how regime types and religion-state arrangements frame questions of religious and political identities in Muslim and Catholic societies. The book proposes a theory for modeling the dynamics of "religiously friendly democratization " processes in which states institutionally favor specific religious values and organizations and allow religious political parties to contest elections. Religiously friendly democratization has a transformative effect on both the democratic politics and religious life of society. As this book demonstrates, it affects the political goals of religious leaders and the political salience of the religious identities of religious individuals. In a religiously charged national setting, religiously friendly democratization can generate more support for democracy among religious actors. By embedding religious ideas and values into its institutions, however, it also mediates the effects of secularization on national religious markets, creating more favorable conditions for the emergence of public religions and new trajectories of religious life. The book anchors its theoretical claims in case studies of Italy and Algeria, integrating original qualitative evidence and statistical data on voters' political and religious attitudes. It also considers the dynamics of religiously friendly democratization across the Muslim world today, through a comparative analysis of Tunisia, Morocco, Turkey and Indonesia. Finally, the book examines the theory's wider relevance through a large-N quantitative analysis, employing cross-national databases on religion-state relationships created by Grim and Finke and Fox.