It is standardly assumed that a religious commitment needs to be based upon religious belief, if it is to be rationally acceptable. In this thesis, that assumption is rejected. I argue for the feasibility of belief-less religion, with a focus on the approach commonly known as “non-doxasticism”. According to non-doxasticism, a religious life might be properly based on some cognitive attitude weaker than belief, like hope, acceptance or belief-less assumption. It provides a way of being religious open exclusively to the (...) agnostic. This thesis consists of an introductory essay and five independent papers. The aim of the introductory essay is to provide a general background and set the stage for the discussion in the papers. Its first major part is about the rationality of religious belief. I assess three major ways of providing rational justification for religious belief: natural theology, the reformed epistemology of A. Plantinga and W. Alston, and voluntarism as advocated by B. Pascal and W. James. I highlight some of the most serious problems associated with these approaches, and argue that these problems are enough to warrant an exploration of belief-less alternatives. The second major part of the introductory essayintroduces belief-less religion and its two main forms: fictionalism and non-doxasticism. Both approaches are presented in some detail, including important accounts and current developments. While I would not deny thatboth approaches can be defended as intellectually feasible and rationally acceptable ways of being religious, I also explain why I think non-doxasticism is to be preferred over fictionalism. Paper I and II concerns the account of non-doxastic religion offered by J. L. Schellenberg. Paper I raises some problems for Schellenberg’s analysis of propositional faith, and presents a way of handling these problems by making faith occasional. Paper II argues that non-doxasticism should be focused on traditional religion rathar than Schellenberg’s simple ultimism. Paper III and IV concerns non-doxasticism on a more general level. Paper III argues for the superiority of non-doxasticism over fictionalism. It contains the argument for exclusive availability, according to which only non-doxasticism is rationally available to the pro-religious agnostic. Paper IV explores the notion of rational, non-doxastic faith, and argues for three desiderata any such faith must meet. Unlike the other papers, Paper V is primarily connected to the first part of the introductory essay, and it concerns the scope and limit of natural theology. It is tentatively argued that perfect being theism lies outside the scope of natural theology, and that its most prominent arguments at best support some kind of deism. (shrink)