Okay, I'm not trying to sound like a pessimest or anything, but I honestly don't believe in world peace. I just don't think it's going to happen. Whenever I hear somebody say "I wish/pray/hope for world peace," I think they're just fooling themselves. Seriously, in our huge world, there is always going to be somebody who wants to get a head of the game by cheating, lying, killing and being generally bad. And there will always be people to join that person. I just don't think a peaceful world is realistic.
But I think that peace with your self is realistic. I've said it once, I'll say it again. You are the only person you can change and come to peace with. And by doing that, you may be able to influence others to do the same. And maybe, just maybe, we'll be able to increase the amount of happy, loving, people.