World Christianity as a historical phenomenon emerged in the last quarter of the twentieth century, showing the global reaching of Christianity physically, numerically, and characteristically. Even though the number of Christians at the beginning of the twenty-first century (around thirty-three percent of the world’s population) has not changed much since the beginning of the century before, the demographic shift and intercultural nature of Christianity have changed its appearance. In just a century, Christianity truly became a world religion (Robert 2009; Kim and Kim 2016). Consider the demographic shift: at the beginning of the twentieth century, as many as eighty percent of Christians lived in the global North, that is, Europe and North America. By the first decade of the twenty-first century, however, at least sixty percent of Christians were from the global South regions (Johnson and Ross 2009: 8), largely previously considered non-Christian except for migrants from the North. While mainly produced by the modern missionary movement from the West, various characteristics of world Christianity have also shown the indigeneity of the different forms of regional Christianity. Assuming that world Christianity is still in transition, especially in theology, this article deals with theological developments relating to the world Christianity phenomenon. It first offers a brief empirical analysis and historical description, then explores the theological phenomena surrounding world Christianity. Two theological developments – in particular, contextual theology and intercultural theology – are identified as the main branch of world Christianity’s theology. The study concludes with a suggestive doctrinal-theological foundation to anchor the theology, namely the doctrine of incarnation.