WHAT is the Sermon on the Mount? It is the moral law of the kingdom of Christ, or in other words it occupies in the New Testament the place which in the Old Testament is occupied by the Ten Commandments. It is thus an excellent example of the relation of the two divine “testaments,” or rather covenants, to one another. There is a sentence of St. Augustine’s on this subject which it would be useful for every one to have constantly in mind. “We do wrong,” he says, “to the Old Testament if we deny that it comes from the same just and good God as the New. On the other hand, we do wrong to the New Testament if we put the Old on a level with it.”[2] This is a general statement of the relation between the two covenants, and it applies especially to the moral law. The moral law of the Old Testament, as it is expressed in the Ten Commandments, was the utterance of the same God who now speaks to us in the person of Jesus Christ. It reappears here in the Sermon on the Mount, but deepened and developed. We may say with truth that the Sermon on the Mount supersedes the Ten Commandments; but it supersedes them by including them in a greater, deeper, and more positive whole. This Sermon on the Mount, then, is the moral law of the new kingdom, the kingdom of heaven, the kingdom of the Messiah. We have been used to think of the Messiah, the Christ, as an isolated figure; but the Messiah whose advent is expected in the Old Testament is only the centre of the Messianic kingdom. Round about the king is the kingdom. The king implies the kingdom as the kingdom implies the king. Thus the way in which Christ announced His Messiahship was by the phrase “The kingdom of heaven is at hand.” And now――now that He has gathered round Him his first disciples――He takes them apart, and there on the mountain He announces to them the moral law of the new kingdom to which they are to belong. Thus it is a law not only for individual consciences, but for a society――a law which, recognized and accepted by the individual conscience, is to be applied in order to establish a new social order. It is the law of a kingdom, and a kingdom is a graduated society of human beings in common subordination to their king.