What do the Scriptures principally teach?

The Scriptures principally teach what man is to believe concerning God, and what duty God requires of man.[1]

2 Timothy 1:13 (NASB)

Retain the standard of sound words which you have heard from me, in the faith and love which are in Christ Jesus.

I learned a five step method for interpreting Scripture:[2]

1.    Grasp the text in their town.

2.    Measure the width of the river to cross.

3.    Cross the principlizing bridge.

4.    Consult the biblical map.

5.    Grasp the text in our town

The point of this is to come to the universal principle taught in the text that is applicable in the lives of everyone, then personally apply the principle in our own lives. There are also a few criteria to observer:[3]

§  The principle should be reflected in the text.

§  The principle should be timeless and not tied to a specific situation.

§  The principle should not be culturally bound. 

§  The principle should correspond to the teaching of the rest of Scripture.

§  The principle should be relevant to both the biblical and the contemporary audience.

The goal is to grasp the meaning of the text that God intended. People make the mistake of hyper-literal interpretation; attempting to apply the meaning meant for the ancient audience, or hyper-spiritualizing the text; creating a meaning that was not intended by God. All of Scripture is inspired by God and is profitable for teaching, for reproof, for correction, for training in righteousness;(2 Tm 3:16) therefore, there is a universal principle in every text of Scripture but that principle is not universally applied in the same way. 

[1] The Shorter Catechism, question 3.

[2] J. Scott Duvall and J. Daniel Hays, Grasping God’s Word 3rd ed. (Grand Rapids: Zondervan, 2012), ch. 2.

[3] Ibid.