This thesis presents the Spanish Empire as seeking to spread a Christian world system - Christendom on a universal scale. By focusing on Spanish America, this thesis seeks to give evidence that a new Christendom was being established in America, one which was sustained through the collection of ecclesiastical revenues. This approach is taken in order to analyze the identities which were forged by the individuals who participated and who were transformed by this empire. Specifically, I focus on the Indigenous and their mixed raced descendants, the castas. Rather than portraying them as passive figures, I seek to give them agency by presenting them as active figures who actively participated within this Christian world system. Through their active participation, a Christian identity was able to be forged. A Christian identity which was not a carbon copy of the Spaniards, but one which was uniquely theirs. Through this Christian identity the Indigenous and their mixed raced descendants were able to blur the lines between who were the conquerors and who were the conquered. This would result in the Indigenous and their mixed raced descendants transforming the Christian world system, from a system which was of European origins, to a system that became distinctly American.