“Hear now,” said he, “how wicked is the action of anger, and in what way it overthrows the servants of God by its action, and turns them from righteousness. But it does not turn away those who are full of faith, nor does it act on them, for the power of the Lord is with them. It is the thoughtless and doubting that it turns away. For as soon as it sees such men standing steadfast, it throws itself into their hearts, and for nothing at all the man or woman becomes embittered on account of occurrences in their daily life, as for instance on account of their food, or some superfluous word that has been uttered, or on account of some friend, or some gift or debt, or some such senseless affair. For all these things are foolish and empty and unprofitable to the servants of God. But patience is great, and mighty, and strong, and calm in the midst of great enlargement, joyful, rejoicing, free from care, glorifying God at all times, having no bitterness in her, and abiding continually meek and quiet. Now this patience dwells with those who have complete faith. But anger is foolish, and fickle, and senseless. Now, of folly is begotten bitterness, and of bitterness anger, and of anger frenzy. This frenzy, the product of so many evils, ends in great and incurable sin. For when all these spirits dwell in one vessel in which the Holy Spirit also dwells, the vessel cannot contain them, but overflows. The tender Spirit, then, not being accustomed to dwell with the wicked spirit, nor with hardness, withdraws from such a man, and seeks to dwell with meekness and peacefulness. Then, when he withdraws from the man in whom he dwelt, the man is emptied of the righteous Spirit; and being henceforward filled with evil spirits, he is in a state of anarchy in every action, being dragged here and there by the evil spirits, and there is a complete darkness in his mind as to everything good. This, then, is what happens to all the angry. Wherefore do you depart from that most wicked spirit anger, and put on patience, and resist anger and bitterness, and you will be found in company with the purity which is loved by the Lord. Take care, then, that you neglect not by any chance this commandment: for if you obey this commandment, you will be able to keep all the other commandments which I am to give you. Be strong, then, in these commandments, and put on power, and let all put on power, as many as wish to walk in them.”
How to Recognise the Two Spirits Attendant on Each Man, and How to Distinguish the Suggestions of the One from Those of the Other.
Source: The Pastor (or "The Shepherd") (New Advent)