The paper concerns the problem of reason and faith on the basis of Christianity. The author points out the Bible as the text which otherwise is rooted in Judaism and Christianity. The starting point for the analysis of reason and faith is the story of Doubting Thomas. The author interprets it as a scene in which the accent does not fall on lack of faith of Thomas but the emergence of "reason on the sidelines." It indicates an intimacy of the unparalleled meeting of Thomas and Christ. To present this moment the author interprets the image of Gerard van Honthorst titled The Incredulity of Saint Thomas. The author shows the particular dangers associated with the use of reason and faith what has an influence on human culture. The paper is an attempt to describe the relationship between faith and reason.