Growth in wisdom...

Growth in wisdom may be exactly measured by a decrease in bitterness.

...study your own failings...

When you are offended at any man’s faults, turn to yourself and study your own failings. Then you will forget your anger.

A gentle answer turns way strife

A gentle answer turns away strife, but the slow to anger pacifies contention.

Anger repressed

Anger repressed can poison a relationship as surely as the cruelest words.