Christianity and colonialism are often closely associated because Catholicism and Protestantism were the religions of the European colonial powers and acted in many ways as the "religious arm" of those powers. According to Edward Andrews, Christian missionaries were initially portrayed as "visible saints, exemplars of ideal piety in a sea of persistent savagery". However, by the time the colonial era drew to a close in the last half of the twentieth century, missionaries became viewed as "ideological shock troops for colonial invasion whose zealotry blinded them", colonialism's "agent, scribe and moral alibi."
Christianity is targeted by critics of colonialism because the tenets of the religion were used to justify the actions of the colonists. For example, Toyin Falola asserts that there were some missionaries who believed that "the agenda of colonialism in Africa was similar to that of Christianity". Falola cites Jan H. Boer of the Sudan United Mission as saying, "Colonialism is a form of imperialism based on a divine mandate and designed to bring liberation - spiritual, cultural, economic and political - by sharing the blessings of the Christ-inspired civilization of the West with a people suffering under satanic oppression, ignorance and disease, effected by a combination of political, economic and religious forces that cooperate under a regime seeking the benefit of both ruler and ruled."
Edward Andrews writes:
Historians have traditionally looked at Christian missionaries in one of two ways. The first church historians to catalogue missionary history provided hagiographic descriptions of their trials, successes, and sometimes even martyrdom. Missionaries were thus visible saints, exemplars of ideal piety in a sea of persistent savagery. However, by the middle of the twentieth century, an era marked by civil rights movements, anti-colonialism, and growing secularization, missionaries were viewed quite differently. Instead of godly martyrs, historians now described missionaries as arrogant and rapacious imperialists. Christianity became not a saving grace but a monolithic and aggressive force that missionaries imposed upon defiant natives. Indeed, missionaries were now understood as important agents in the ever-expanding nation-state, or "ideological shock troops for colonial invasion whose zealotry blinded them."