Nowadays, we face growing truculence and extremisim under the banner of religious beliefs. In Islam and in Christianity such groups like Salafis and fundamentalists who claim religious purity draw erroneous conclusions from religious texts, which, in some cases, result in adopting extreme positions on religious matters. On inquiry, we find that, besides the political motives, there are different factors behind the extremism and violence to which these two groups restort. Among the most important of them is the adoption of literalist approach to interpreting religious texts.With the aim of creating a fair compromise between Islam and Christianity regarding their attitudes towards religious extremism, the paper investigates some instances of the tendency towards literalism in inferring religious teachings from the Quran and the Bible, and evaluates the relation between choosing this method and the emergence of religious extremism. Establishing the fact that there is direct relationship between Salafists’ literalism which has incited many current brutalities and that of Fundamentalists is among the most important findings of this research.