This review paper aims to reveal the role of different types of religiosity based on research addressing religiosity in terms of in-group and out-group distinction within the scope of Terror Management Theory (TMT). Studies point out two important results of the phenomenon: the first is the fact that general religiosity focusing on only one aspect of religiosity (religious belongingness, afterlife belief, etc.) to measure religiosity increases worldview defense, supporting the hypothesis of mortality salience. The second is the fact that different religious orientations (intrinsic, fundamentalist, etc.) cause various reactions, depending on their unique characteristics when mortality is salient. In the current study, possible reasons for the differences between research findings are discussed. In order to clarify the roles that different types of religiosity play in terror management, a classification based on the strong-flexible and exclusive-inclusive poles of the “belief” and “belonging” dimensions suggested by Sarouglu has been proposed. It has been argued that religiosity types would function in terror management in different ways, depending on the classification in which they are placed. For example, when the religious worldview is threatened, the strong-exclusive pattern (e.g., religious fundamentalism) can lead to more negative reactions, while the strong-inclusive pattern (e.g., intrinsic religiosity) can be associated with positive processes in inter-group relationships. Future research on this classification and types of religiosity can provide unique contributions to developing TMT. On the other hand, knowing the roles of different forms of religiosity in managing existential concerns may be of therapeutic benefit in coping with death, bereavement, grief and related processes.