Among the issues that have an effective role in the dialogue between Islam and Christianity and how the followers of these two religions can have, is to explain the place of the fate of the followers of the two religions, In this article, an analytical, comparative method seeks to explain the foundations and The common religious beliefs of Islam and Christianity, which according to the religious texts and the specific causes and circumstances of the followers of both can be saved. Motahhari's professor believes non-Muslims who have not gained to the right religion of time (Islam), if this lack of knowledge and achievement is not due to their fault and shortcomings, or their prejudices, and are arbitrarily opposed to the right to surrender, according to Godliness And the truthfulness of their intentions and their moral and moral deeds can be called salvation, from which they have been interpreted as "innate Muslims. " And in the Christian religion, Karl Rahner, of the contemporary Catholic Christian theologians, by proposing the theory of the "inclusiveness of salvation, " and refreshing and redefining the concept of "eternal grace" within human beings, the non-Christians who respond to this divine grace and their inner voice and conscience Given and believing in God and doing good moral deeds, they are called "unknown Christians" and can be saved.