Why has the reality of other religions become a big problem for Christianity? In the past, Christianity has been able to largely ignore other religions but in recent decades, not just the reality, but the vitality of other religions has become a challenge. This accessible book tackles a number of questions arising from these changes: is belonging to one religion rather than another merely a matter of cultural preference?; is salvation the same among all religions?; and what can be learned from other religions? Considering wider issues of how modernity has defined "religion," Gavin D'Costa provides a substantial critique of secular ways of controlling religions, and shows how Christianity is very well suited to deal with religious plurality at the doctrinal and social level. The book makes a decisive contribution to debates about the clash between Islam and the West, arguing that the major threat to religious freedoms come from secularism, and that Islam and Christianity both have the resources to develop a vibrant and pluralist "public square" informed by intellectual debate. By engaging with the core questions and suggesting a pathway through the various answers that have been proposed in recent years, this is an ideal introduction to the field, and one which will help stimulate ideas and discussions.