From Path to Sanity, by Dee Pennock
Your environment is given to maximize your discovery of what and who you are, to maximize your realization of your sin and need for God, to maximize your incentive to reach out to him and receive Christ in you, the hope of glory (Col. 1:27).
Nobody can elicit anger in you if there is no anger in you to inflame--as we see from the saints who experienced abuse and martyrdom without any anger. All people can do is spark a passion we already have in us, like anger. You can't lose your temper unless it's there in you to be lost. All our saintly counselors tell us, to use the words of one: Many passions are hidden in our souls, but they are discovered only when the object or cause which arouses them appears (Hesychius of Jerusalem).
If we have persons in our environment who cause our inborn passions to flare up in an obvious way, it can be a blessing for us. This disturbance, like the angel's troubling of the water in the pool of Bethesda (Jn. 5:2-9), can send us into the pool of God's mercy for help. Without such trouble we might not have stepped in and been healed. Healing is the purpose of conditions that reveal our passions. The discipline and trouble of this life, says John of Damascus, were designed to enable us to cast aside the evil that was foreign and contrary to our nature.
If a sin is not yours, you can't repent and be healed of it. We can't be healed of someone else's sin, only of our own. [. . .] Listen to what the saints teach. They say that whenever you keep feeling bothered by someone, tempted to impatience or anger or revenge, it's not because of the sin in the other person. No, it's never because of the sin in others; it's always because of the sin in you.
If you get into the habit, every time someone else bothers you, of asking Lord Jesus Christ forgive me and show me my sin, you'll be quite surprised at the adjustments in yourself that can be made...You'll find that repentance always works, enlightenment always comes, and the circumstances are always changed.