The study presents an analytical comparison between the Mosaic laws and the ethical teaching of Jesus Christ in Matthew 5:21-48 as a paradigm for the contemporary Christians. The objectives of this study are to reveal the standard of Jesus’ teaching over the Old Testament teaching on laws to counter the erroneous belief in the early church that, Christians were not giving standard teachings to their members. That, New Testament is adulteration of the Old Testament. Various teachings, most especially the Mosaic laws in the selected passage revealed that, as Jesus as Rabbi taught his followers strong and hard teachings or doctrines than the Mosaic Rabbis and other religious leaders who claim to be righteous and holier. The methods employed for the study include: historical, narrative and descriptive. The historical method helped the researcher to compare and contrast between the decalogue and Mosaic laws with the sermon on the mount. The narrative method helped to narrate the six antitheses, vis-à-vis; murder, adultery, divorce, retaliation, oath the relevance of the ethical teaching to the contemporary society with emphasis on Christians who are expected to live an outstanding life. The study concluded with emphasis on the necessity of the ethical teaching in the society and church in the contemporary era.