An angry person is a willing epileptic

Venerable John Climacus ~ The Ladder of Divine Ascent
Step 8 ~ On Freedom from Anger

¶11. An angry person is a willing epileptic, who due to an involuntary tendency keeps convulsing and falling down.
¶12. Nothing is so inappropriate to those repenting as a spirit agitated by anger, because conversion requires great humility, and anger is a sign of every kind of presumption.
¶13. It is a mark of extreme meekness, even in the presence of one’s offender, to be peacefully and lovingly disposed towards him in one’s heart, then it is certainly a mark of hot temper when a person continues to quarrel and rage against his offender, both by words and gestures, even when by himself.

Be gentle, kind

Venerable Seraphim of Sarov

You cannot be too gentle, too kind. Shun even to appear harsh in your treatment of each other. Joy, radiant joy, streams from the face of him who gives and kindles joy in the heart of him who receives. All condemnation is from the devil. Never condemn each other. We condemn others only because we shun knowing ourselves. When we gaze at our own failings, we see such a swamp that nothing in another can equal it. That is why we turn away, and make much of the faults of others. Instead of condemning others, strive to reach inner peace. Keep silent, refrain from judgement. This will raise you above the deadly arrows of slander, insult and outrage and will shield your glowing hearts against all evil.

Be gentle, humble, simple

St. John of Kronstadt

As far as is it possible, be gentle, humble and simple to all, considering yourself, without hypocrisy, to be spiritually below everyone. Pride is the reason for a cold, pompous and insincere manner towards those whom are considered to be below us, or those from whom we hope to derive some benefit. When people speak ill of you and you feel resentment, it means that you are proud, and pride must be eliminated from your heart by worldly dishonour. Therefore, do not resent and hate those who speak ill of you, but try to love them as you would love people who benefit you, and pray for them. Maintain a peaceful and loving disposition towards your brother even if he deprives you of your last shilling; show him that, above all, you love God's image in him. However most people are angry when they are deprived even of a very small part of their property!