Where does man get the authorization from God to change the meaning of Scripture?
It couldn't have been that man just takes it upon himself to change what God has said into what man wishes had been said, right? There must be something written somewhere by God that gives man the authority and the omniscience and omnipresence possessed by God to change what He wrote into something that men can find more acceptable, right?
Where did God give man that authority?
IMHO man does not have the authority but The Holy Spirit inside you does have the authority.
John 16:12-15 (NIV) 12 I have much more to say to you, more than you can now bear. 13 But when he, the Spirit of truth, comes, he will guide you into all the truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come. 14 He will glorify me because it is from me that he will receive what he will make known to you. 15 All that belongs to the Father is mine. That is why I said the Spirit will receive from me what he will make known to you.
Another neat analogy is that Bethlehem is in your heart where Our Lord Jesus Christ is born.