The Sermon on the Mount contains many comparisons. In this book, the functions of these comparisons are studied by the methodology called comparative characterization. Characterization is the way a character is characterized in a narrative. Comparative characterization is the characterization of a character using comparisons. In comparative characterization, another character is used as a foil to bring out a characteristic trait of a concerned character. Jesus characterized the ideal disciple in the Sermon on the Mount with many descriptions and imperatives. To characterize the ideal disciple Jesus used many comparisons and highlighted the characteristic features that embody the ideal disciple. The many comparisons used in the Sermon on the Mount are identified in this study through comparative characterization. In addition, the teleological purpose of the comparisons, which is to play as foil to the characterization of the ideal disciple, is identified and highlighted. Thus, this study identifies Jesus' characterization of the ideal disciple and his complex portrayal of the ideal disciple with the many uses of comparisons in the descriptions and imperatives of Jesus in the Sermon on the Mount.