this study from yesterday's NYT shows how abstract thoughts prompt literal physical responses. (thanks to James for the link.)
i have a friend who refuses to say things like, "this job is killing me," because of the potential impact on the body's response.
while i initially disagreed, scripture and this scientific claim from the Times seem to substantiate that somewhat. the book of proverbs says words can give life and take it (18:21). genesis tells us that God spoke the universe into existence (1:3). the only weapon in the armor of God is the Word (Eph. 6:10-20).
i have a theory that words might be the most powerful thing in the universe. while tone and body language convey intent, words alone are a force to be reckoned with. if words are power, and power corrupts... then what?