When they fast, I will not hear their cry; and when they offer a burnt offering and a grain offering, I will not accept them: but I will consume them by the sword, and by the famine, and by the pestilence.
Read Chapter 14
Athanasius the Apostolic
AD 373
Hence it is that they are always writing, and always altering their own previous statements, and thus they show an uncertain faith, or rather a manifest unbelief and perverseness. And this, it appears to me, must be the case with them. Since they have fallen away from the truth and desire to overthrow that sound confession of faith that was drawn up at Nicaea, they have, in the language of Scripture, “loved to wander and have not restrained their feet.” Therefore, like Jerusalem of old, they labor and toil in their changes, sometimes writing one thing and sometimes another, but only for the sake of gaining time, and that they may continue enemies of Christ and deceivers of humankind. - "Letter to the Bishops of Egypt 1.6"
In the Gospel, the Savior commends the unjust steward because, although he defrauded his master, he acted wisely for his own interests. The heretics in this instance pursued the same course. When they saw how great a matter a little fire had kindled, and that the flames applied by them to the foundations had by this time reached the housetops and that the deception practiced on many could no longer be hid, they asked for and obtained letters of commendation from the church, so that it might appear that until the day of their departure they had continued in full communion with it. Shortly afterward the distinguished Anastasius succeeded to the pontificate. But he was soon taken away, for it was not fitting that the head of the world should be struck off during the episcopate of one so great. He was removed, no doubt, that he might not seek to turn away by his prayers the sentence of God passed once for all. For the words of the Lord to Jeremiah concerning Israel applied equally to Rome:...
You see, then, that fasting is certainly not considered by the Lord as a thing that is good in its own nature, because it becomes good and well-pleasing to God not by itself but by other works. Again, from the surrounding circumstances it may be regarded as not merely empty but hateful, as the Lord says: “When they fast, I will not hear their prayers.” - "Conference 3.21.14"
Although God is by nature good, yet he is also just, and as the case requires. He knows how to heal but also how to strike. He brings peace, but he brings about evil. He desires repentance, yet he commands Jeremiah not to intercede for the sinful people, since, he says, even if they fast, I will not hear their prayer. - "On Purity 2"
