That's why we call it "faith."
The God who created the universe and everything therein, the alpha and omega, the beginning and the end, the all powerful One, is not so helpless as to allow His Word to be screwed up by a committee of men.
Every word of the Bible is there because it is the Word of God. Every word that is not in the Bible is not there because it is not the Word of God.
Personally, I don't believe that because of the contradictions and misstatements. Given that the only written words that God gave us are on the Ten Commandments which have never been found, everything else has gone through a human filter.
Song of Solomon is interesting reading, but it's hard to imagine God writing it. How long has it been since your church focused on it?
That does not mean all the other copies and versions are not the Word of God ~ just that only one was selected.