In this lecture I will ask why early Christian thinkers placed so much emphasis on getting right how they envisaged the world as “created.” I will argue that for these thinkers what is said about the creation (and thus about humanity) is inseparable from what is said about the nature of God, and thus learning to imagine the creation properly is intrinsic to Christian faith. The main thinkers considered will be Irenaeus of Lyons and Augustine of Hippo, with some mention of Origen of Alexandria and Gregory of Nyssa.