Evil company is always to be shunned; because it leads to lust and anger, illusion, forgetfulness of the goal, destruction of the will (lack of perseverance), and destruction of everything. (Narada Bhakti Sutra)
With everything we do in life we identify ourselves. Here is a man who says harsh words to me. I feel anger coming on me. In a few seconds anger and I are one, and then comes misery. Attach yourselves to the Lord and to nothing else, because everything else is unreal. Attachment to the unreal will bring misery. There is only one Existence that is real, only one Life in which there is neither object nor [subject].
I know, to banish anger altogether from one's breast is a difficult task. It cannot be achieved through pure personal effort. It can be done only by God's grace.
If we ourselves remain angry and then sing world peace, it has little meaning. First, our individual self must learn peace.
This we can practice. Then we can teach the rest of the world.