"And I will give them one heart, and I will put a new spirit within Ezekiel 11:19.
Centuries ago a heathen said that true love and friendship can appear only between good men, but unfortunately he did not know what makes a good man. When God's mercy intends to accomplish oneness, He first makes the people new. "And I will give them one heart, and I will put a new spirit within" Ezekiel 11:19.. Genuine peace is a fruit of the Spirit-- it inevitably sanctifies before it unites.
Finally, we see that every part and purpose of the sinner's love is carnal, not spiritual. Augustine pitied Cicero for not having Jesus Christ in his life far more than he admired him for his eloquence. This, then, is what draws a heavy black line through the carnal man's peace and unity-- there is nothing of God and Christ in it.
Do carnally minded people aim at the glory of God? Is it Christ's command which binds them together? No, there is still a voice involved-- but it is not God's. Their own relaxation or fleshly favor is the primary motive. Peace and unity are such welcome guests, and pay so well for their lodging, that they motivate men with no grace at all to keep up an external peace among themselves. In a word, the peace of the wicked will not last long because it lacks strong cement. Stones may lie together for a while without mortar, but not for long. The only lasting cement for love is the blood of Jesus.
The Gospel of peace is a strange text to preach contention from, yet Paul speaks of this very thing: "Some indeed preach Christ even of envy and strife" Philippians 1:15. These men seem to have forgotten that their Lord who sent them is Himself the Prince of peace! Their work is not to blow a trumpet of confusion or sound an alarm to battle but rather to call for a joyful retreat from the dreadful fight against God and one another..”Quoted material from, ”The Christian in Complete Armour Daily Readings in Spiritual Warfare” by Gurnall and James S Bell. http://www.moodypublishers.com/pub_productDetail.aspx?id=41823&pid=53617