After providing a survey of related literature and of Protestant antecedents in Colombia during the colonial and early national periods, the dissertation examines the expansion of foreign missions in Colombia during the early twentieth century. The main body of the work describes various aspects of Protestant life after 1930, including life stages, self-image, construction of community, and societal responses. Although many Colombians reacted adversely to Protestants, a general atmosphere of tolerance is evident. Protestants suffered greatly during the mid-century Violence, but not to an unusual extent in comparison to Colombians in general. However, the Protestants' oppositional religious identity and their sense of vulnerability during that period made their psychological experience of the Violence somewhat unusual. Through the end of the twentieth century, Protestantism provided an oppositional space in which many Colombians found a sense of security, empowerment and optimism in the face of tremendous challenges in a violent land.