And he shall stand and feed in the strength of the LORD, in the majesty of the name of the LORD his God; and they shall abide: for now shall he be great unto the ends of the earth. And this man shall be the peace, when the Assyrian shall come into our land: and when he shall tread in our palaces, then shall we raise against him seven shepherds, and eight principal men. Micah 5:4-5 (KJV)
It will be great if there were no hunger or poverty in the world. It will be great if there were no wars or hatred among people. And perhaps, by the end of humanity Christ will restore such peace on earth. But for now, there is a peace that he is busy restoring; that is a peace between us and YHWH. Yes! There is great evil in this world; greedy capitalists, politicians, terrorists, et cetera. But there is a greater evil, there is sin and punishment. It manifests in our relentless unbelief; we may know God intellectually but may feel far from him in our inner most selves. Christ came to restore this peace, between sin and the Holy wrath of God. Peace on earth will be established after there is peace between us and God. The advent is a wonderful reminder that the Son of God came to establish an everlasting peace, tied to Him, and through Him, in an eternal bond.