Shorter Catechism Q. 2. What rule hath God given to direct us how we may glorify and enjoy him? A. The Word of God, which is contained in the Scriptures of the Old and New Testaments, is the only rule to direct us how we may glorify and enjoy him.
Commentary: If we are going to accomplish our chief end of glorifying and enjoying God, then we will need to know how to do it. And the only knowledgeable and trustworthy guide to tell us how to do it is God who is good and all-knowing. The Word of God, therefore, is the only rule to direct us how we may glory and enjoy God. The question, therefore, is where do we find the Word of God or what is the Word of God (see WLC #3), which can serve as the rule to direct us?
There are several plausible and not so plausible answers such as the light of nature or natural law, feelings, conscience, church tradition, a persons’ inner divine light (Quakers), prophets and apostles, providence (signs, open/closed doors) and prayer. Since the Word of God needs to be interpreted, further answers may include the church’s interpretation of the Word of God (examples: creeds, confessions, the Pope speaking ex cathedra), study Bibles, and/or biblical scholars.
For various reasons, none of the above can serve as the rule today even though some knowledge of God continues to be revealed in a few of them. The only rule today is the written Word of God, that is, the Scriptures of the Old and New Testaments. This does not imply that there aren’t subordinate helps and guides like pastors, teachers, creeds and confessions, but it does mean that all of Scripture (not just the New Testament) and only Scripture is the only infallible, inerrant and sufficient rule of our faith and obedience. Consequently, Scripture alone is the “supreme judge by which all controversies of religion are to be determined (WCF 1.10).”
Scripture alone, therefore, is the source and standard of our beliefs and practices. We derive our theology and ethics from Scripture, and we evaluate them by Scripture.