ectypal.net

...Scripture acquires certainty as God’s own Word with us by the testimony of the Holy Spirit. Though proofs and reasonings are of great value, this testimony surpasses them by far; it is more excellent than all reason. Just as God can only witness concerning himself in his Word, so his Word does not find belief in the hearts of human beings before it is sealed by the internal testimony of the Holy Spirit. The same Spirit who spoke through the mouths of the prophets must work in our hearts to persuade us that they faithfully proclaimed what had been commanded by God. The Holy Spirit, accordingly, is the “seal” and “guarantee” for confirming the faith of the godly. If we have that testimony within us, we do not rest in any human judgment but observe without any doubt as if we were gazing upon God himself in it—that Scripture came from the mouth of God through the ministry of human beings.