"The misuse of the tongue can apparently render all other graces in my life impotent...one single wrong word and all the words we've ever spoken crumble into so much hypocrisy in the eyes and ears of those who listen to us"
"'blessing and cursing'... we should never minimize these words. It not the kind of thing we say when we sneeze, 'bless you'. These are words that describe the serious covenantal determined operations of God of either judgment that will lead to hell or of grace that will lead to heaven. And you say there we are standing praising God and in the next moment we are cursing men and women have been made in his image"
http://www.desiringgod.org/Blog/1423_conference_video/#LinksToThisPost