Religion and science have long been in a discussion in which both have tried to justify themselves against the other. In that relationship, only religion seems to show more of the ability to transform the other side into something useful in a religious meaning. This ability of religion has been enhanced in new religious movements formed in the West, and it seems to be also the case for many new religious movements in East Asia. However, in the context of Western colonialism, new East Asian religious movements might have justified themselves through science in different patterns in comparison with the norms of Western ones. The paper endeavours to investigate how two new East Asian religions born under the pressure of colonialism, Caodaism in Vietnam and Donghak in Korea, in their doctrinal dimensions, had tried to respond to Western science soon after they were established. As a result, the paper suggests a critical revision of the worldview theory of Ninian Smart in order for it to be applicable in the study of new East Asian religious movements.