In an age of environmental crisis, ecological theologians call for the “ecological conversion” of humanity. This article, a work of practical theology, plays on the grammatical ambiguity of Mark 10:15, in which disciples are told to “receive the kingdom as a child,” to argue that ecological conversion is a twofold conversion to the child. One conversion is a turn to the well-being of children in an age of climate crisis, which involves an adult personal transformation into the role of caregiver—and thus greater maturity. The other conversion is a recovery of certain childlike capacities, including presence in the moment, interdependence in relationship, urgency, animism, and love of the small. The article draws on Pope Francis’ encyclical Laudato Si’, discussions of childhood by the nineteenth-century Protestant theologian Friedrich Schleiermacher, and contemporary explorations of children and childhood, including the author's own experience of caregiving with children.