Revelation 16:12

And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the East might be prepared.

Every new plague seems to be more deadly than the preceding one: And the fourth poured out his vial upon the sun, and to him was given to scorch men with fire; and men were scorched with great heat, and blasphemed the name of God, who has the power over these plagues, and did not repent to give Him glory. Here we see that, by reason of the testimony of the Lord's witnesses, the kingdom of Anti-Christ is plagued with unbearable heat. As Luther and his coworkers, and their pupils after them, proclaimed the message of salvation, of justification by grace, in all its simplicity and power, the rays of this pure doctrine proved too glaring and too scorching for the Roman hierarchy. Instead of letting these raps sink into their hearts and work true conversion in them, they deliberately resisted the Holy Ghost, continued in the kingdom of Anti-Christ, and blasphemed the name of God in uncontrollable rage. But still the Word of Grace is proclaimed, still the plague is increasing their obstinacy, still they persist in hardening their hearts.

And the end is not yet: And the fifth poured out his vial upon the throne of the beast, and his kingdom became covered with darkness, and men gnawed their tongues in anguish, and blasphemed the God of heaven for their pains and for their ulcers, and did not repent of their works. The Anti-Christ, whose seat is at Rome, had boastfully flattered himself that his doctrine would be the sun, the light to illumine the whole world. But he found his plans going awry on account of the free proclamation of the Gospel of liberty, which has, to a large extent, eclipsed his false doctrines. The result was that he and his minions bit and gnawed their tongues in anguish, that they were consumed with a pain which they thought unbearable. But so deeply has the Pope, and his followers with him, become immersed and-submerged in his errors against the fundamental doctrines of Christianity that they blame God for their condition, for their pains and for their ulcers, that they blaspheme Him and harden their hearts against repentance: they persist in their anti-Christian works.

Nor is the situation changed by the sixth plague: And the sixth poured out his vial upon the great river Euphrates; and its water was dried up, that the way of the kings from the rising of the sun might be prepared. The kingdom of Anti-Christ is here compared to the ancient kingdom of Babylon, whose capital was situated on the river Euphrates. This city was taken by Cyrus by the simple device of giving to the water of the river anew bed and entering the city through the path thus laid open. In the same way the power and glory of anti-Christian Rome was dried up through the preaching of the Gospel and the way thus opened both to penetrate into the city and level its bulwarks and to open the way to freedom for many peoples and nations. It certainly seemed for a while as though the power of Anti-Christ had been broken forever.