The paper is a documentary research evaluating the two theories of ‘rational choice’ and ‘religious marketing’ in sociology of religion and Islam’s relation with these theories. The rational choice theory is affected by a wide range of philosophical, economical, behavioristic and sociological topics by which the social activists’ behavior is explained based upon the cost-benefit rational approach. On the other hand, relying on the principle of the freedom of choice, for religious marketing theory, the desirable conditions for development and continuation of religion is formation of religious marketing. Rationality is the common base of both theories based on which religion is chosen in free marketing and in religious pluralism and this is carried out within a process of cost-benefit analysis. Therefore, the more developed are the religious institutes, the more is religious vitality. Despite of wide expansions of these two theories in sociology of religion, they are addressed by some criticisms such as having weakness in explaining structural and macro levels, the problem of theoretical and experimental generalization, little attention to emotion, values and human beliefs, religious outwardly viewing, tautology in given cases, and the most important one is theoretical and experimental explication in the context of secularism. Also, from Islam’s perspective, the most important criticism is formation of these two theories in the context of secularism.