The Spanish colonial project of the sixteenth century was undergirded by a unique political structure that was critical to its success. I argue that this political structure is characterized by a system of checks and balances that was enforced by the competing religious and economic motives for the Spanish presence in the Indies. After establishing the conditions of the political environment, this paper looks at the evangelization projects proposed by important theologians and historical figures of the time to determine how they justified and envisioned the Spanish presence in the Indies. All but one of the figures discussed prioritized either the economic or the religious motives of the conquest, resulting in their failures to adapt to the political environment and the ultimate weakness of their proposals. Jose de Acosta is the sole theologian to take a middle ground when developing a project for evangelization and colonization that took into account both the religious and economic motivations for Spanish presence in the Indies.