Why Study Theology: Good & Necessary Consequence
The Westminster Confession of Faith begins with what many have deemed some of the most well articulated statements concerning the doctrine of Scripture. And incorporated right into the confession’s understanding of Scripture is a brief, little clause on how one might do theology. The clause, which has garnered much thought over the centuries, was placed there as an expression defending the sufficiency of Scripture in all of life. In chapter 1, paragraph six, the Westminster divines state that “The whole counsel of God concerning all things necessary for His own glory, man’s salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequences may be deduced from Scripture...”
As Robert Letham has said, the phrase “by good and necessary consequences...is a profoundly important statement.” It points to the need for careful thought in reading, preaching, and thinking about the Bible.” In fact, he makes the point that “it mandates theology.” And Letham is right. No preaching or theological work can be done well unless the church is willing to deduce from Scripture good and necessary consequences. Louis Berkhof, commenting on the idea and history of dogma, writes that “the word dogma is derived from the Greek verb dokein. In classical Greek the expression dokein moi meant not only, ‘it seems to me’, or, ‘I am of the opinion’, but also, ‘I have come to the conclusion.’”  It is here then where we see the good and necessary function of theology and dogmatics; an enterprise of reason finding it’s authoritative grounding in God’s authoritative word.
To many people today, this idea of theology and dogma leaves a bad taste in their mouths, especially when connected to the idea of reasoning, necessary or not. William Cunningham, writing a little over 200 years after Westminster, noted that many express an extreme “dislike to precise and definite [theological] statements upon the great subjects brought before us in the sacred Scriptures. This dislike of precision and definiteness in doctrinal statements sometimes assumes the form of reverence for the Bible - as if it arose from an absolute deference to the authority of the divine word, and an unwillingness to mix up the reasoning and deductions of men with the direct declarations of God.” He continues though that “we believe it arises... from a dislike to the controlling influence of Scripture, [and] from a desire to escape...the authority... of [the Bible’s] regulating power as an infallible rule of faith and duty.” He concludes that “it has been the generally received doctrine of orthodox divines, and it is in entire accordance with reason and common sense, that we are bound to receive as true, on God’s authority, not only what is ‘expressly set down in Scripture,’ but also what, ‘by good and necessary consequences, may be deduced from Scripture.”
Theologians such as the Scottish puritan George Gillespie defended this way of logically reading Scripture by pointing to verses like Matthew 22:32 where Jesus himself defends his theology of the resurrection by quoting Exodus 3:6, “I am the God of Abraham, the God of Isaac, and the God of Jacob.” It is from this verse that Jesus necessarily deduces that the patriarchs, though long dead and buried, are actually alive, reasoning from the Exodus passage that “God is not the God of the dead, but of the living” (Matt. 22:32).
Of course, Gillespie, a strong Calvinist, would have boldly upheld Deuteronomy 29:29 as a foundational basis for proper hermeneutical investigation, agreeing with Calvin that God’s word “may be for us the sole rule of righteousness, and the truly just cause of all things.” In other words, he would never want in mere speculation to overstep the bounds and rule of Scripture and “exult in [mankind’s] own vanity.” And yet, Gillespie was confident to declare that a “reason captivated and subdued to the obedience of Christ and... standing to scriptural principles... [can be] convinced and satisfied with the consequences and conclusions drawn from Scripture.” To Gillespie and the other Westminster divines, this was a good and godly thing.
And it wasn’t just the Puritans who defended such a hermeneutic either. Three centuries earlier William of Ockham wrote that Christians must believe “what is said in holy Scripture, or what can be inferred therefrom through necessary reasoning.” In fact, much earlier in defense of what was and is a central tenet of Christian dogma, many of the early church fathers employed such logical deductions in their defense of the Trinity. No one can read the history of the doctrine of God’s triunity without seeing what a major role good and necessary consequence played in coming to dogmatic conclusions.
Athanasius gave grounds for this in his defense against the Arians. It was argued by the Arians that terms like “Trinity” and “one in essence” were unbiblical words, thus rendering the doctrine unbiblical. But Athanasius wisely responded that such wording and phraseology “if accurately examined, will be found to be altogether a representation of the truth and especially if diligent attention be paid to the occasion which gave rise to these expressions, which was reasonable... [and] that, even if the expressions are not in so many words in the Scriptures, yet, as was said before, they contain the sense of the Scriptures, and expressing it, they convey it [rightly].” For men like Athanasius, it was necessarily good to derive certain terms to describe and defend what was implicit, if not always explicit, in Scripture itself.
Again, William Cunningham picks up on this theological deduction seen in the early church when he states that “this is indeed the process by which our whole system of theological opinions ought to be formed; and there is need for special care and caution in conducting this process, in regard to topics which can be known only from Scripture...[but] we are fully warranted in concluding, upon the authority of Scripture that the Son... has a divine nature or substance.”
From the examples we have from Jesus himself, from the early church and medieval church, as well as the Westminster divines, good and right theology can and should be done by seeing the “good and necessary consequences” derived from Scripture.
Today, with much conversation revolving around one’s ‘worldview’, or even in some circles whether or not theology is an appropriate endeavor, this idea of “good and necessary consequences” takes on renewed import. For Christians of all stripes, a reading of the Bible which fails to apply its explicit principles in a reasonable way, deductions which pertain to godliness and right living, can be detrimental, especially in a world where many of our everyday activities are not explicitly spoken of in Scripture. How Christians are to think about and interact with issues such as the transgender movement, the rise of social media, new science, or whatever, a thorough grounding in the truths of Scripture, truths which are expressly set down in its explicit teaching as well as derived from necessary consequences, will help us live wisely to God’s glory. Indeed, as John Frame clarifies, “to the extent that we disobey the applications of Scripture, we disobey Scripture itself.” For what more is the doing of theology then the application of Scripture to all of life?
All of God’s word is sufficient for “all things necessary for His own glory, man's salvation, faith and life, and is either expressly set down in Scripture, or by good and necessary consequence can be deduced from Scripture: unto which nothing at any time is to be added, whether by new revelations of the Spirit, or traditions of men.”
Stephen Unthank (MDiv, Capital Bible Seminary) serves at Greenbelt Baptist Church in Greenbelt, MD, just outside of Washington, DC. He lives in Maryland with his wife, Maricel and their two children, Ambrose and Lilou.
 Robert Letham, The Westminster Assembly, 139.
 Louis Berkhof, Systematic Theology, 18.
 William Cunningham, The Reformers & the Theology of the Reformation (Edinburgh, Banner of Truth, 2000) pp. 523
 ibid. 526
 Institutes of the Christian Religion 1.17.2. and 1.6.2
 George Gillespie, Treatise of Miscellany Quotations, 100-101 as seen in C.J. Williams, “Good and Necessary Consequences in the Westminster Confession”, pp. 175-6.
 William of Ockham, Dialogue against Heretics, bk. 2, chap. 5 in George H. Tavard, Holy Writ or Holy Church: The Crisis of the Protestant Reformation (London: Burns & Oats, 1959) pp. 35.
 See Jaroslav Pelikan’s The Emergence of the Catholic Tradition (100-600), pp. 211-25
 William Cunningham, Historical Theology vol. 1 (Edinburgh, Banner of Truth, 1994) pp.284-85