First of all the passage does not say that he came to kill.
Secondly I want to tell you a story I heard about which is a great example of Matthew 10:34-39. Don't remember the specifics but if you are really interested I can look into it and hopefully provide you with them but I remember the key part. There was this girl who I believe was muslim, who turned to faith in the Lord Jesus Christ. Her dad did not like this very much and threatened to chop off her hands if she didn't turn back to Islam. So, he chopped off her hands because she knew Jesus was Lord and the savior. To me this does not sound like peace, but like a sword. And it sounds like a man against his daughter, a member of his own household.
Thatis not however how the story ends, after this, her dad accepted Jesus Christ, and was saved, as I believe did also her mother and perhaps her family (I forgot if her family did or not). So as you can see the taking away of peace, and bringing of a sword was not the final part of the story for this daughter and father. On the contrary it was to use this small life to bring about much more important eternal life for daughter, father, and mother, (and hopefully more in the family and to people who heard/hear/READ about it).
I would like to tell you please look for God, if you pray to Him with a sincere heart really wanting to find Him, he will reveal Himself to you.
I don't want to sound arrogant or full of myself, but I know God is real, and I know Jesus is Lord. I have experienced things and heard about things, and I know God is real.
I am going to provide you with some links below please watch them if you love truth!
http://www.youtube.com/watch?v=JZR022_GbzU For people who think the earth is old/believe in evolution
www.wayofthemaster.com (need to have flash installed to watch opening movie on this one)
http://www.allaboutreligion.org/polycarp-video.htm (If you like this and history, you can get Drive Thru History Rome if you want to..., Greece and the Word, Turkish Delight, East meets West, and the American History Series from - www.drivethruhistory.com)
The Privileged Planet, The Lazarus Phenomenon, The Perfect Stranger, & Another Perfect Stranger are great movies.