The impatient and the patient must be admonished in different ways.

The impatient must be told that, by refusing to rein in their own impetuosity, they will find themselves dragged into many abysses of iniquity which they would not have sought out, for fury drives the soul to places it would not wish to go, and the soul, perturbed, acts without knowing what it is doing, only lamenting once it realizes what it has done. It must also be said to the impatient that, by rushing headlong under the impulse of their passions, they act as if they were beside themselves, and so find it difficult to realize the harm done. When they offer no resistance whatsoever to that which disturbs them, they even mar the good they had accomplished with a calm spirit, and in a sudden impulse destroy everything they had built up with great effort over a long period of time. […]

On the other hand, the patient must be urged not to complain inwardly about what they endure outwardly. Outwardly, they offer a perfect sacrifice of great value; inwardly, they must not allow the poison of evil to corrupt it. Men may not realize it, but the divine gaze discerns sin, and such complaining would be all the more serious a fault because, in the eyes of others, it takes on the appearance of virtue. It is therefore necessary to tell patient men to strive to love those they must endure; lest love fail to accompany patience, and thus the virtue they display be transformed into a worse sin: that of hatred.

ST GREGORY THE GREAT. Pastoral Rule. Part III, Ch.9