Nigel Biggar’s controversial 2023 book Colonialism: A Moral Reckoning is explicitly founded on his concept of ‘Christian realism’ in assessing the legacies of European colonialism and, by implication, European-led Christian mission. This paper explores what this realism means, contrasting it with Jacques Ellul’s stricter realism in his stronger criticisms of colonial violence. However, I contend that the missing piece in both these assessments of Christian history is the need for a realistic analysis of the post-colonial growth of the church in the Global South (Africa in particular). Lamin Sanneh’s emphases on mission as translation and on indigenous agency provide a welcome counterpoint to Biggar and Ellul’s focus on what the West may or may not have done.