In recent decades an increasing number of theologians have asserted that the Western world has moved from a Christendom era to a post-Christendom era, as evidenced by the magnitude of which it has been discussed in theological texts. This article analyzes the writings of Lesslie New-bigin with the aim of understanding the relationship between Christendom and his theological project, particularly how he evaluated the rise of Christendom and, finally, proposes how Newbigin envisioned the role of the church in a post-Christendom society.