(In this post, I use the angle-bracket notation to stand for memes.)
Good point. I stipulate that there is only <God>.
Here is another reason your analogy with memes like <war> is still not very good; there are actual wars.
However, I still think that the fact that people use <God> proves that <God> is useful, like <absolute zero>. Does it bother you when people say "absolute zero"? How about "the average man"?
> Second most destructive cocept; communism.
<Communism> is second on the list, eh? Pretty impressive for a meme that has had less than two centuries to do its dirty work. If the Soviet Union hadn't collapsed, it could have had a shot at #1! I'm glad you've thought about it and it wasn't just an off-the-cuff remark; it must be pretty hard to rank these memes.