In verse 18 of the last chapter of Revelation, was the adding to and taking away from “this book” the book of Revelation or the entire word of God?
It is barely possible that the writer intended it to apply specifically to the book of Revelation; but it is a principle that applies to all the inspired writings, and I believe it was written in these last verses of the book that naturally closes the revelation of God, that as a two-edged sword it might guard from change or modification the whole revealed will of God.
Moses says: “Ye shall not add unto the word which I command you, neither shall ye diminish aught from it, that ye may keep the commandments of the Lord your God which I command you.” (Deut. 4:2.) It is repeated in Deut. 12:32; Josh. 1:7. Prov. 30:5, 6 expresses it thus: “Every word of God is pure: he is a shield unto them that put their trust in him. Add thou not unto his words, lest he reprove thee, and thou be found a liar.” It is repeated a hundred times in one form or another in the Old Testament. If the Old Testament law — temporal in its rule, sealed by the blood of animals — was thus sacred and guarded from sacrilegious touch by the hand of man, how much more sacred the perfect and everlasting law of God, given through the word that was with God and sealed by the blood of his only begotten Son! The mission of Jesus, as announced by John, was to thoroughly purge his floor, separate what had been added by human tradition and burn it as chaff, so he could fulfill only the perfect will of God. He condemned all the traditions of the elders and all human traditions in religion, showing that even washing the hands as religious service when not commanded by God was sin. (Matt. 15.)
To displace God’s order under the Jewish dispensation with an order of men was to despise the law of Moses; to turn from the law sealed by the blood of Christ, to take from it or add to it, is to trample underfoot the blood of the Son of God and do despite to the Spirit of grace. To change the word of God by adding to or taking from it as God has given it is to assume the prerogative of God and claim to be wiser than he and to be possessed of more than his authority. I believe God intended that warning to apply to the whole of his written will; and if that specific command did not, the same principle and warning is stamped upon almost every page of revelation.