Thus Saith the Lord

Speaking on behalf of God is a serious thing, prone to abuses. Yet to shut out the possibility of it all together, is to miss out on a tremendous blessing. As Beth Moore says, "Our repulsion over the abuses should not be our out for practicing present participle faith"
I have experienced the blessing of others speaking a blessing and a "word" over my life, which proved to be Scriptural and life-giving. I have also been part of a community during the disillusionment and pain of an apparently unfulfilled prophecy.
The only way to attempt to be a mouthpiece for God, is to acknowledge the fact that one's own voice is also at play. One's own compulsion to control or relieve one's own inner anxiety could just as easily be at play in delivering a word for someone from on High. As long as we are aware of, and dealing with our issues, we should remain engaged in seeking to hear directly from God and being willing to humbly and lovingly speak to others on His behalf.