This thesis takes a comparative approach in examining the reactions of residents of three seventeenth-century Christian missions: Natick in New England, Kahnawake in New France, and Ohkay Owingeh, New Mexico in New Spain, to religious colonialism. Particular attention is paid to their religious beliefs and participation in colonial warfare. This thesis argues that missions in New England, New France, and New Mexico were spaces of Indigenous culture and autonomy, not due to differing colonial practices of colonizing empires, but due to the actions, beliefs, and worldviews of Indigenous residents of missions. Indigenous peoples, no matter which European powers they interacted with, reacted to Christian worldviews that permeated all aspects of European colonial cultures.