This has cropped up a few times now in the last month or so. No slam...just an observation. Ray has expressed the opinion that if the churches believe it and/or practice it, it is almost certainly wrong. That's a tough lesson, but it is bearing out as true to me.
Mat 16:19 I will be giving you the keys of the kingdom of the heavens, and whatsoever you should be binding on the earth shall be those things having been bound in the heavens, and whatsoever you should be loosing on the earth, shall be those having been loosed in the heavens."
Mat 18:18 "Verily, I am saying to you, Whatsoever you should be binding on the earth shall be those things having been bound in the heavens, and whatsoever you should be loosing on the earth shall be those loose in heaven.
Those are from the Concordant Literal Version. The other Literal versions I have access to are in agreement in the verb tenses. The bold text is a direct translation of the Greek, the light text is added for 'clarification'. The tense says to me that the action of loosing, binding, and forgiving originates in the Heavens, and not on earth. The action on earth which Christ is preaching is agreement with God, not convincing Him to do something. This is consistent with the model prayer.
I can't go much past the grammar of the verses, except to remember what evil the middle church did to the Grace of God in applying them.