In Faith Seeking Action, author Gregory Leffel links a description of the church as a global movement with a description of contemporary social movements that are actively challenging today's societies, such as the environmental, global justice, and identity movements. Not surprisingly, Christian communities and communities of social activists share much in common as they each work to enrich their societies. It is natural then to ask what missionally-concerned Christians may learn from social movements about the public role of their churches, the connection of their beliefs to social change, and the mobilization of their people. It can also be asked how these often divided communities may find ways to collaborate around common actions rooted in such shared values as peace, justice, life, and the integrity of the environment.

Building on growing interest in the field of missiology and its "missional church" concept, Leffel has created a dialog between the church as a social actor and social movements. Along with introducing movement theory to mission studies, Leffel introduces a new way of addressing the issues involved in the church's engagement with society, a concept he calls missio-ecclesiology. Of interest to those seeking vital ways to live out their faith in the world—missiologists, missional church leaders, and street-level workers alike—this work fuels fresh thinking about the church's role in cultural and social change.