The Sermon ended with mentioning some of the difficulties which the subjects of "The Kingdom of Heaven" would have to meet in the practice of godliness. In the first place, in order to become His subjects they would have to enter through a narrow gate, upon a path which few would find. For whilst, on the one hand, "Wide is the gate and broad is the way that leadeth to destruction, and many there be that go in thereat," on the other hand, "Strait is the gate and narrow is the way which leadeth unto life, and few there be that find it" (S. Matt. vii. 13, 14). And when they had entered upon this narrow way, He warned them that they must be on their guard against being misled by foolish professors, because mere profession of obedience would neither prove them to be subjects of His Kingdom, nor win for them admission "in that day" into His glory and joy, "Not every one that saith unto Me, Lord, Lord, shall enter into the Kingdom of Heaven, but he that doeth the will of My Father which is in Heaven" (S. Matt. vii. 21-23). Therefore they must set to work to do the will of God, and so be true subjects of Messiah's Kingdom. And then, as doers of His words, and not hearers only, they would be building like wise men "upon a rock" (S. Matt. vii. 24). The description thus given by the King Himself of the character and life of His subjects sets vividly before us the difficulties which a Christian must overcome. It may not be always easy to decide whether the expression "Kingdom of Heaven" refers to the Kingdom as it is now on earth, or as it will be hereafter in Heaven; but it is clear that our Blessed Lord would teach in this Sermon both the difficulty of becoming a professing Christian at all, and also the need of earnest strivings after holiness in order that a subject of His Kingdom of Grace should find a welcome when that Kingdom shall have become the Kingdom of Glory. And when we think of the very different standards hitherto aimed at either by Jews or Gentiles, we see at once the reason which prevented so many of His hearers from accepting "The Kingdom of Heaven." For it is clear that a man who had been brought up either as a Jew or as a Gentile would have to lay aside almost all his previous habits and modes of thought--he must become a new man altogether--to enter in. Who then would enter in? Who would become subjects of the Kingdom of Heaven?