Tim Challies takes up a thoughtful examination of that question. I think he hits on a lot of good points here, and examines things fairly. My conclusion is pretty similar to his - no, smoking is not necessarily sinful, though an addiction to it could be. The Bible has nothing to say about the subject whatsoever, so I would have major concerns with someone who would say that it unequivocally is sinful - that is the territory of legalism. Can good arguments be made against smoking? Sure - though Challies shows that these reasons aren't as airtight as they might seem when viewed with consistency across the spectrum of the Christian life. In any regard, it's a good article to get you thinking about how we define sin. Check it out, and if you've got thoughts on the issue, let me know in the comments.
I'm a follower of Christ, an heir of the Reformation, and a Baptist - in that order. My wife Heather and I have been married since 2005 and are the proud parents of a little girl. I work as an Aviation Technical Publications editor. From 2005 to 2009 I served as Minister to Youth at Hazelwood Baptist Church in Louisville, Kentucky, and I'm now actively pursuing church planting.
Soli Deo Gloria!