This first book of the Spirituality for the World series recasts what Christians call the missiological question first and foremost to those who would be true believers, including all who might wish to bear appropriate witness to their faith in a pluralistic world. The first question to be asked is less, who to evangelize and seek to convert, and more, what does it mean for me as a true believer to be evangelized and converted today? Witness: Converting Worlds invites us to imagine afresh what it means to be ready to share our faith and that this requires ongoing conversion religiously and spiritually, not just in our heads and minds but in our hearts, in our actions, and in our communities and societies. In dialogue with one of the earliest Christian evangelists, St. Luke, Witness urges that the most compelling expressions of faithful religious witness in our age is manifest in lives that find themselves continually converted as the earliest Christian evangelists and missionaries found themselves repeatedly transformed to their core along the Jesus way.