I don't consider myself a hateful person but I just don't like who I am when I'm sarcastic. There's something innately disrespectful about sarcasm. I can't think of a time that my sarcasm built someone up but I don't have to think hard to cite instances when it cut someone down. Sarcasm is good for a cheap and easy laugh but usually at someone's expense. I think I'm most prone to use sarcasm as a defensive weapon when I feel like I'm backed into a corner . . . it just seems like a natural and easy way out of such situations. I'm also prone to use it when I disagree with another, perhaps as a way to diffuse the conflict but with the more likely consequence of alienating the other person and anyone else who hears me.
The Bible has a lot to say on this general topic and Ephesians 4:29 NIV is a good word on the power and purpose of your words. If others didn't struggle with this, I guess there wouldn't be so many books on the topic, too. Two to consider are 30 Days to Taming Your Tongue by Deborah Smith Pegues and a new book by Ace Collins titled Sticks and Stones, Using Your Words as a Positive Force. I don't know about you, but I can use all the help I can get in this area.