Many of the doctrines central to Christianity have important philosophical implications or presuppositions. In this article, we begin with a brief general discussion of the relationship between philosophy and Christian dogma, and then we turn our attention to three of the most philosophically challenging Christian doctrines: the trinity, the incarnation, and the atonement. We take these three as our focus because, unlike (for example) doctrines about providence or the attributes of God, these are distinctive to Christian theology and, unlike (for (...) example) the doctrine of original sin or the Real Presence of Christ in the eucharist, these have been the subject of a great deal of discussion over the past couple of decades. (shrink)