Answering the objection that "Word-of-mouth tradition is never said to be theopneustos, God breathed, or infallible," one critic of sola scriptura responded, in part, that:
Scripture uses various terms to describe divinely originated revelation, e.g., “the word of God,” (1 Thess. 2:13) “the Spirit of your Father speaking through you” (Matt. 10:20); “in spirit” (Matt 22:43); “filled with the Holy Spirit” (Acts 4:8), and many others. None of these descriptions is of less divine origin and authority than theopneustos. (Robert A. Sungenis, "Point/Counterpoint: Protestant Objections and Catholic Answers," in Sungenis, ed. Not by Scripture Alone: A Catholic Critique of the Protestant Doctrine of Sola Scriptura [2d ed; Catholic Apologetics International, 2009], pp. 193-294, here, p. 227)
In a footnote (p. 227 n. 52) to the above, we find the following admission from Protestants, similar to that of James White and others, that the authors of the New Testament accepted, en par with inscripturated revelation (not mere subordinate authorities) other sources of revelation and authority:
Note the following statements by prominent Protestant apologists: Greg Bahnsen: “Therefore, according to the Scripture’s own witness, the verbal form and content of the apostolic publication of the gospel message should be deemed wholly true and without error.” Inerrancy of the Autographs. Carl F.H. Henry: “Inerrancy pertains only to the oral or written proclamation of the original inspired prophets and apostles” (quoted in Inerrancy of the Autographs). J.I. Parker: “The concept of biblical inspiration is essentially identical with that of prophetic inspiration…It makes no difference whether its product is oral or written. When in the past evangelical theologians defined God’s words of inspiration as the producing of God-breathed scriptures, they were not denying that God inspired words uttered orally as well. Indeed, in the case of prophets and apostles, the biblical way to put the point is to urge that the words in which these men wrote or dictated are no less God-given than the words they shared orally with the individuals and congregations, for the spoken word came first…and the Spirit speaking in them directed both what was said and how it was said (Matthew 10:19-20)” (The Adequacy of Human Language). Norman Geisler: “Whereas it is true that the oral pronouncements of the living apostles were as authoritative as their written ones (1 Thess. 2:13)…” Also, in the section, “Direct Claims For The Inspiration Of The New Testament,” Geisler states: “Earlier he had reminded them, ‘It was the word of God which you heard from us’ (1 Thess. 2:13)” (From God To Us, Geisler and Nix, pp. 43, 45). Bruce Milne: “This high view of their teaching and preaching applied as fully to their written as to their spoken statements” (Knowing the Truth, p. 32).
