When we study God, whether is through the Scripture, or a book expounding the ideas of Scripture, it is important to remember what the study of theology is, why it is important, and what the purpose of the study is. The purpose of theology is what I’m considering now.
Because God is the creator and sustainer of all of the universe (John 1:3; Colossians 1:17) and because God is one (Deuteronomy 6:4) having revealed Himself, His will, His mind to us in Scripture, there cannot be multiple meanings within Scripture. Because God is the God of truth (Psalm 31 :5) and Logic (John 1:1) all that is revealed in Scripture is logically connected as a cohesive whole . The Christian religion is a system of propositional truths delivered by the God of truth Himself.
R. J. Rushdoony stressed the necessity of Scripture’s logical unity:
“There can be no systematic theology if the God of Scripture is not a coherent unity, and if His word is not a coherent whole. An incoherent God, who has elements of unrealized potentiality in Himself and who cannot speak a necessarily infallible word, is incapable of being either the foundation of any systematic theology or of being God. Thus, those who find in Scripture only flashes of insight and a sometimes incoherent movement toward realization, see no God at all. They are simply mining a vast deposit of earth in the hopes of mining a few nuggets of gold in all that void.”
We ought not look at Scripture as a list of disjointed facts, some of which are applicable and some not. All of Scripture is God breathed and profitable (2 Timothy 3:16-17). The questions the theologian (and every Christian is a theologian) must ask himself is, “How do I apply this bit of truth to my life?”
There are two purposes in the study of theology: First, to learn more of the God revealed in Scripture that you may better worship Him. In fact, when one studies Scripture, he must mull in his mind the deep truths contained, he must carefully consider how they relate to one another. One ought to philosophize as he studies Scriptural truth. Gordon Clark used an analogy that is fitting:
“The beauty of philosophy is its circularity, for one may begin at any point and by constantly making progress return to the same point again. In the meantime he will have made the circuit of things seen and things unseen, and he will have discovered some of the beauty of both. The universe, with its vast astronomy, with its thinking reed, with the history of politics of nations, is God’s handiwork and has been excellently well made. At least, so the Christian believes. But how can one know that it is beautiful unless thought is expended, unless time is taken to examine it, unless the purpose of its darker hues and the lines of its actors are understood? After an artist produces his piece, the public gains appreciation only by seeing how each stroke of the brush, or each line of the poem, fits the whole. A work of art is an integrated whole; it is not a disjointed aggregation of unrelated things; and knowledge and appreciation depend on an understanding of the plan according to which it was formed. No doubt the public fails fully to appreciate and fully to understand the genius of the artist; but it seems irrational, tragic, inconceivable that an omnipotent artist should let his fairest flower be born to blush unseen and waste its desert sweetness on the desert air. In other words, philosophizing is an act of worship.”
God has given to us in Scripture a body of systematic thought. It is not enough when approaching theology to be content with the parts; we must understand the whole, and in so doing worship the God revealed in the whole.
The second purpose in the study of theology is that of application. God didn’t only paint a portrait of Himself for us to admire. He also gave us the law and the covenant. He placed us by His providence, in a corrupt world to be the salt and light of it. Christ said, “Ye are the light of the world… Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.” (Mathew 5:14-16) Scripture also says, “To the law and to the testimony: if they speak not according to this word, it is because there is no light in them.” (Isaiah 8:20)
The world is staggering around in the darkness of their own reasoning. It is our commission as ambassadors of Christ to teach and apply the law and the gospel. There is no aspect of life that does not fall under jurisdiction of God’s Word. Therefore there is no aspect of life to which Scripture does not apply. Some more from Rushdoony:
“Systematic theology must of necessity deny, because God is sovereign, that there are any neutral facts, or any areas of neutrality. All factuality is God-created and God governed and interpreted. All facts are therefore theological facts, and every area of life, thought, study, and action is a theological concern. Education, politics, science, the arts, the vocations, the family, and all things else are theological concerns. A theology which does not involve itself in every area in terms of the sovereign God and His infallible law-word cannot be systematic: it is merely abstract.”
If then when we study theology we are not driven by intense adoration to worship when we read of God’s work and attributes, or if we are not motivated and educated to apply God’s Word to every aspect of life, business, parenting, personal piety, ethics, church, civil government, economics, and every other facet of existence, then our study of theology is in vain, for we have missed its purpose.
– Ben Murch
 “Logos” translated as “word” in the KJV conveys the meaning of “logic or reason”.
 Rushdoony, The Necessity for Systematic Theology, pg. 11
 Clark, Chirtsian View of Men and Things, pg. 5
 Rushdoony, The Necessity for Systematic Theology, pg. 17