In Roman times, blocks of text were commonly written just as blocks without even wordspacingnevermindpunctuation to help the reader to interpret them. Orators using such texts as notes for a speech would prepare carefully so that they were familiar with the content and didn't come a cropper over a confusion between, say, therapists and the rapists. As we entered the Christian era and sacred texts were widely read (by priests if not by the rest of us), it became ever more important to remove any likelihood of misinterpretation. To a potential murderer or adulterer, for example, there is a world of difference between 'If you are tempted, yield not, resisting the urge to commit a sin' and 'If you are tempted, yield, not resisting the urge to commit a sin'. And the only surface difference is the positioning of a comma. So yes, you SMS-addicts and 'let it all hang out' Sixties children, punctuation does matter. And, contrary to what people who tear their hair out over apostrophes believe, it is there to help - to clarify meaning, to convey emphasis, to indicate that you are asking a question or quoting someone else's words. It also comes in handy for telling your reader when to pause for breath.