The writers of the Westminster Confession have given us solid ground on which to not only do theology, but to do a Scripturally based theology which is authoritative and guiding for our faith and life.
The Westminster Confession of Faith begins with one of the most well articulated statements concerning the doctrine of Scripture. And incorporated right into the Confession is an ever so brief clause on how one might do theology. The clause was placed there to be an expression defending the sufficiency of Scripture in all of life. In chapter 1, paragraph six, the Westminster divines stated 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 put it, 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. It mandates theology.” And Letham is right. No preaching or theological work can be done rightly unless the church is willing to deduce from scripture good and necessary consequences in order to bring about doctrinal clarity and practical application.
Louis Berkhof underscores this very mandate to do theology when he writes that “the word dogma is derived from the Greek verb dokein… [expressing the idea] not only, ‘it seems to me’, or, ‘I am of the opinion’, but also, ‘I have come to the conclusion’, ‘I am certain’, ‘it is my conviction’. And it is especially this idea of certainty that finds expression in the word ‘dogma’… [Thus] religious dogmas are based on divine revelation (either real or supposed), and are therefore authoritative.” It is here where we see the good and necessary function of theology finding it’s authoritative grounding in God’s authoritative word.
William Cunningham (1805-1861), reflecting back upon the Westminster Confession, noted that many people express an extreme “dislike to precise and definite [theological] statements upon the great subjects brought before us in the sacred Scriptures. This dislike to precision in doctrinal statements, sometimes assumes the form of reverence for the Bible… [with] an unwillingness to mix up the reasonings 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 its regulating power as an infallible rule of faith and duty.” He concludes that “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.”