On hearing the words “canon addition,” we are likely to think of the addition of books, such as the apocrypha, to the Bible. We might think of the canonization of tradition by Roman Catholicism. R. C. Sproul writes of the claims of characters like Pat Robertson and Oral Roberts of receiving “words of knowledge,” alleged supernatural revelation from God, and laments the credulity of people who swallow these claims apparently without thought. We might look critically on such people, wondering how they can be so foolish. But many of those who ridicule such gullibility fall for a subtler form of the same kind of canon addition. Sproul writes:

   But it gets more subtle. We hear respected Christian leaders claiming that God has “spoken to them” and given special guidance and instructions upon which they are duty bound and to act and obey. They are careful to note that that this divine speech was not in audible form and there is a disclaimer that this is not a new “revelation.” yet the message which is “laid on the heart” is so clear and powerful that to disobey is to disobey the voice of God. I am not speaking here of the work of the Holy Spirit by which he illuminates the text of scripture in such a sharp manner as to bring us under conviction or direct our paths. But here the Spirit works in the Word and through the Word. I am speaking of the speaking of the Spirit that men claim is working apart from the Word and in addition to the Word.
   Through such claims are more often that not attended by the disclaimer that they are not revelation, the way they function is as revelation so that the distinction between them and bona fide revelation is, in actuality, a distinction without a difference.

—R. C. Sproul, Scripture Alone (P&R Publishing Company, 2005), 60.