"Scripture interprets Scripture"
"Reformed theology...attempts to interpret the whole counsel of God in view of the principle that Scripture interprets Scripture. In other words, that which is clearest and is treated with the greatest significance in Scripture interprets those passages that are more difficult and less central to the biblical message...the goal is to say what Scripture says and to emphasize what Scripture emphasizes. If Scripture itself coalesces around the revelation of Christ as the fulfillment of the Father’s plan of redemption, as Jesus himself said, then we are hardly imposing our own nonbiblical theological grid on Scripture in saying that Scripture is centrally a witness to Christ. But we do not begin with a conception of Christ that we have already formed independently of Scripture, by which we judge the Scriptures (deductively); instead, we come to learn from the Scriptures (inductively) that Christ stands at their center." -- Michael Horton, God of Promise, pp. 12,13