Explanation of the Sermon of Jesus on the Mount

The Sermon of Jesus Christ on the Mount contains certain features which are fundamental in all of his teaching. The nature of the Kingdom of God is set forth in this great discourse. One difficulty arises in the reading of the Sermon on the Mount. How can such an ideal be attained? It might be possible to obey a set of rules, like the rules of the Pharisees, but how is it possible for sinful men to attain purity of heart? The righteousness of the Kingdom of heaven exceeds by far the "righteousness of the scribes and Pharisees." How can such righteousness be attained?...
If anyone will piously and soberly consider the sermon which our Lord Jesus Christ spoke on the mount, as we read it in the Gospel according to Matthew, I think that he will find in it, so far as regards the highest morals, a perfect standard of the Christian life.