Matthew 5:9 “How blessed are those who make peace! for they will be called sons of God."
Only a man with a new heart, a pure heart can be a peacemaker.
This man must be delivered from all self-concern.
He does not look at everything based on what it does to him personally.
We tend to look at things as to how they affect us.
He recognizes that other people are under the control of powers and principalities.
He has pity on them.
His only concern is the glory of God.
He is prepared to suffer injustice in order to glorify God.
He says, “what matters is the glory of God.”
If his suffering leads to that then he will endure it.
He does not need to express his mind.
In fact, he learns not to speak.
He keeps control over his tongue.
No gossip.
He views every situation in the light of the Gospel.
You must go out of your way looking for ways to make peace.
You may have to humble yourself before your enemy.
This is a dead serious summary of chapter 11 in Studies in the Sermon on the Mount by D. Martyn Lloyd-Jones.