John Piper, I just don't understand...

Perhaps my charismatic friends can help me understand this better, because I don't get it.  If I am having a small group study and someone says, "I have a word from the Lord for you..." then I can't take that to mean anything other than...a word from the Lord.  That is, if its really a word from God, then should I not get a bible with blank pages at the end and write these "words from the Lord" under the heading, "the 67th book of the Bible: New words from the Lord?"

It is either from God or it isn't.  Call it an "inlking, spiritual impression, vision" or whatever you want.  But if God is speaking, then God is speaking.  It is a "thus saith the Lord" and it should be taken as nothing other than this.  If its not this, then why not call it what it is?  "I really have something on my heart that i'd really like to share with you guys."  See?  Wasn't that easy?  The substance of the encouragement would be just the same and effective, without the qualifier "from the Lord."  And furthermore, the consequences are far less devastating if you turn out to be wrong. That is, what happens when you get really honest with yourself in deciding that this wasn't a "word from the Lord," but simply a product of your own God-given wisdom and discernment?