I usually avoid linking to text, because they often fall short of the experience of listening to a speech. While the text of tonight's speech will not equal its delivery, it was so good it really does stand on its own.
http://www.realclearpolitics.com/articles/2008/08/the_american_promise.html
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson