Quest. How shall we know the doctrine of the gospel concerning Christ to be yea, undoubtedly true?
Ans. 1. I answer, how do we know the sun shines? I know it by its own light, and by a light that I have in my eye. There is an inward light joined with the outward light. So it is in this business, how do we know divine truth out of the book of God to be divine? By the light in itself, by the majesty of the Scriptures, by the consent of the Old and New Testament, by the opposition of the enemies, and the confusion of them at the last that have been opposers of it, by the miraculous preservation of it, and the like; but especially by the powerful work of it on the heart, by the experience of this blessed truth. I know this to be an undoubted truth, I find it quelling my corruptions, changing my nature, pacifying my conscience, raising my heart, casting down high imaginations, turning the stream of nature another way; to make me do that which I thought I should never have done, only because I have a strong light of divine truth and comfort. There is this experience of Christ, that a man finds in his soul. It sets him down that he can say nothing, but that it is divine truth, because he finds it so. – Richard Sibbes, An Exposition of 2 Corinthians 1