I. The text teaches us that there are certain things which hinder the spread of the Redeemer's kingdom, spoken of here as valleys, hills, mountains, rough places, and crooked ways. The obstacles to the spread of the Redeemer's kingdom are so numerous, that I must not even attempt to name them, but refer, as an illustration, to heathenism and idolatry abroad, and to ignorance and vice at home. The heathenism we are trying to remove; and that yawning valley of ignorance we are, by God's grace, as a nation, trying to fill up; but our national vices, which are like mountains, we are also commanded by God to level and to remove. Take the vice of intemperance. (1) Intemperance hinders the progress of God's kingdom at home. (2) It is also a hindrance to the spread of the Gospel abroad. How is it that though eighteen hundred years have passed since the Redeemer made His great provision, and gave us the command to carry the glad tidings to all, midnight darkness rests upon most of the human family? (a) There is a want of means.(b) There is a want of men. (c) There is a want of success on the part of those who are already in the field. With all those reasons strong drink has something to do.
II. It is the duty of the Christian Church to sweep this mountain away. (1) The Church must,if she would hold her own. There is no neutrality in this war. (2) The Church must, if she would please her Master.
III. The text puts before us the glorious result. "Thy kingdom come "is our cry. Here is God's answer: "Set to work; lift up the valley, bring down the mountain, make the rough places plain and the crooked places straight, and then I will come." God waits for man. As soon as the Church is prepared to do the Lord's bidding, the world shall be filled with His glory.
C. Garrett, Loving Counsels,p. 142.
The imagery of the text appears to be drawn from the journey-ings of Israel to Canaan. That great event in their national history was constantly before the mind of Isaiah, and is presented in his writings with ever-varying illustration. Let us
I. Compare this prophecy with the history of the Exodus. The prophecies of God's Word shine both before and behind. They not only illumine the darkness of futurity, but they reflect a radiance back on the page of history. So here. In the desert the Gospel was preached to Israel (as St. Paul says) in types and ordinances, and especially by that great act of their redemption out of Egypt. In this was a perpetual type of the Redeemer's work of salvation, a foreshadowing of the inspired song, "Comfort ye, comfort ye My people, saith your God." In the ordinances given by the dispensation of angels might be heard "the voice of one crying in the wilderness, Prepare ye the way for our God."
II. Isaiah used the message as an illustration of his own ministry. He too, living now probably in the idolatrous reign of Manasseh, felt himself in a spiritual desert. Led by faith he sees afar off, and the seer is himself transported into that bright future. Just as heralds announced the coming of an Oriental king, and pioneers prepared his march across hill and vale and desert plains, so would Divine Providence lead His exiles home, removing all obstacles from their path, and overruling the designs of their enemies.
III. The words of Isaiah certainly point on to Gospel times; for John the Baptist distinctly announced himself as "the voice of one crying in the wilderness, Prepare ye the way of the Lord." This preparation, in a spiritual sense, he accomplished by his personal ministry.
IV. But even in John's day the words had a wider signification. Not only the land of Israel, but the Gentile world, even all flesh, was then being prepared to see the salvation of God. Providential agencies were even then at work preparing Christ's way among the Gentiles, as it were constructing a road for the march of Christianity through the desolate regions of heathendom. The two most powerful agencies were Greek literature and Roman dominion.
V. The prophecy sheds a lustre on the world's future. The Christ has indeed come to earth, but it was to suffer and to die. Once more in this wide desert the "glory of the Lord shall be revealed," and not one but "all lands shall see it together."
S. P. Jose, Oxford and Cambridge Undergraduates' Journal,May 13th, 1880.
References: Isaiah 40:3-5. A. Rowland, Christian World Pulpit,vol. xxi., p. 323; H. P. Liddon, Old Testament Outlines,p. 200.