There may be a theology without the Scriptures — a theology of nature, gathered by painful, and slow, and sometimes doubtful processes from what man sees around him in external nature and the course of history, and what he sees within him of nature and of grace. In like manner there may be and has been an astronomy of nature, gathered by man in his natural state without help from aught but his naked eyes, as he watched in the fields by night. But what is this astronomy of nature to the astronomy that has become possible through the wonderful appliances of our observatories? The Word of God is to theology as, but vastly more than, these instruments are to astronomy. It is the instrument which so far increases the possibilities of the science as to revolutionize it and to place it upon a height from which it can never more descend. What would be thought of the deluded man, who, discarding the new methods of research, should insist on acquiring all the astronomy which he would admit, from the unaided observation of his own myopic and astigmatic eyes? Much more deluded is he who, neglecting the instrument of God’s Word written, would confine his admissions of theological truth to what he could discover from the broken lights that play upon external nature, and the faint gleams of a dying or even a slowly reviving light, which arise in his own sinful soul. Ah, no! The telescope first made a real science of astronomy possible: and the Scriptures form the only sufficing source of theology.
~ Benjamin Breckinridge Warfield