Cyril of Alexandria

(in Esai. 40. lib. 3.) But suppose some one should answer, saying, How shall we prepare the way of the Lord, or how shall we make His paths straight? since so many are the hindrances to those who wish to lead an honest life. To this the word of prophecy replies, There are some ways and paths by no means easy to travel, being in some places hilly and rugged, in others steep and precipitous; to remove which it says, Every valley shall be filled, every mountain and hill shall he brought low. Some roads are most unequally constructed, and while in one part rising, in another sloping downwards, are very difficult to pass. And here he adds, And the crooked ways shall be made straight, and the rough ways shall be made smooth. But this was in a spiritual manner brought to pass by the power of our Saviour. For formerly to pursue an Evangelical course of life was a difficult task, for men’s minds were so immersed in worldly pleasures. But now that God being made Man, has condemned sin in the flesh, all things are made plain, and the way of going has become easy, and neither hill nor valley is an obstacle to those who wish to advance.