The practice of patience guards us against losing our presence of mind. It enables us to remain undisturbed, even when the situation is really difficult. It gives us a certain amount of inner peace, which allows us some self-control, so that we can choose to respond to situations in an appropriate and compassionate manner, rather than being driven by our disturbing emotions.
If you will think about what you ought to do for other people, your character will take care of itself. Character is a by-product, and any man who devotes himself to its cultivation in his own case will become a selfish prig.