Paul's Strong Voice

I am very perplexed by Paul. He most definately teaches love and unity and yet he uses some of the most vicious terms. He calls men dogs and workers of evil. Those are terms I would reserve for when I feel no love for someone. I understand that Paul is trying to communicate that these things that are being said to the contrary of the Lord are wrong. However, his name calling is not helping the new converts to do anything but alienate and hate those that may be mis-understanding grace. It is an appeal to emotion. He could just have easily put down the ideas without the insults hurrled at the "knife- happy circumcizers." The Lord does tell us to hate the sin and to push it away. He was even provoked to call the hypocrites vipors, I just can't help but wonder where to draw the line. If I stood in a town square and shouted that anyone believing outside of my own perseption of right was a dog, my ministry would be over. No one would listen to me talk about loving my enemy, unity, or the peace that I have inside. I am sure I have a lot to learn about how to hate sin properly, but when I think about the confused people in the world I do not feel hatred, only compassion. I am really learning alot from Paul, or should I say really being confused alot by Paul.