As a minister I firmly believe that I am not allowed to preach what is not in the Bible. It is an exciting enough book as it stands.
No one has a right to adjust the Gospel or revise God's plan for his church.
In too many places where the Bible is being thumped and doctrine is being argued until three in the morning, the Spirit of that doctrine is missing.
William Law (an Anglican from the 1700's): "Read whatever chapter of Scripture you will, and be ever so delighted with it -- yet it will leave you poor, as empty and unchanged as it found you unless it has turned you wholly over to the Spirit of God, and brought you into full union with and dependence upon him."