In my personal experience whenever I have a conversation with someone who is agnostic or Atheist, they always seem to have one specific verse in the Bible memorized. That is "Judge not". Nobody ever likes the idea of being judged, or condemned, especially by a bunch of seemingly judgmental Christians who are always breaking their own rule. What doesn't seem to be realized is that the message of the Bible is God's judgment on man. That is the message to be delivered. Does this make the deliverer of the message judgmental? Perhaps sometimes, although it shouldn't.
JM - Romans 12:17-21 - I like it. Now, if everyone could take a leaf out of those verses....we'd all be a little happier, and a whole lot nicer to one another....at least thats what I've taken from it!