The Christian mysteries, which consist of such doctrines as the Incarnation and the Trinity, pose a problem for anyone who seeks to reconcile the tenets of Christianity with reason. As Leibniz puts it, the mysteries are incomprehensible, improbable, and against appearances. Why should a reasonable individual believe in such mysteries? By answering this question, one responds to the objection that Christianity requires individuals to embrace patent nonsense. Leibniz maintains that the mysteries, although incomprehensible, can be explained sufficiently to justify belief in them. But how can the mysteries be both incomprehensible and explicable? In this paper, I will develop a Leibnizian account of why belief in the mysteries is justified.