Well, at least your consistent. - Edit 1
Before modification by Joel at 25/12/2010 06:20:11 PM
Just because peace on Earh is unobtainable doesn't make its pursuit any less laudable. We strive to realize our ideals and, hopefully, become better people for it. If nothing else, Christmas is a good reminder of that.
I agree with the first sentence. I partially agree with the second. I mostly disagree with the third.
Hard to separate them. I'm not sure what holiday is better suited to remind us to work for what no human alone can ever achieve (maybe Easter...?), and if it's an ideal we can't achieve alone, coming as close as possible makes us better than we otherwise would be (or, maybe, just possibly maybe, helps us understand that not everything is about us, another excellent Christmas lesson). If it doesn't, what constructive result could there be to chasing a dream we can never obtain?
As for which came first, perhaps that's a discussion for another time; suffice it to say I disagree on the grounds that it depends on perspective. 
I. . . .
Thereby hangs the tale, perhaps, but let's not blame that on the holiday, eh...?