God has given us everything that is necessary for his own glory, i.e., that we would glorify Him and see His glory, our salvation and our life of faith and obedience is contained in the Holy Scripture. These things are called the whole counsel of God and this is found either expressly or necessarily in the Word of God. By expressly, the Confession means by direct commands and teachings (e.g. the Ten Commandments, Baptism, the Lord's Supper). By necessarily contained, the Confession refers to principles, applications and implications of Holy Scripture. We are not only to obey the direct commands of Scripture, but also whatever is implied and is based upon the teaching and commands of Scripture. The Lord Christ uses this principle when He proves the resurrection of the dead from the fact that the Patriarchs are alive before God in heaven (Matt. 22:23-33). Resurrection was not in Exodus 3:6, but it was a necessary and a valid implication.
The whole counsel of God is not to be tampered with. No new revelations of the Spirit neither the traditions of men should be added to it because the canon is closed. God has given His last word to the church and world in His Son (Heb. 1:1-2). Then the Confession comes again to the necessity of the Holy Spirit in connection with Scripture. The inward work of the Holy Spirit is not only necessary to convince us that the Bible is God's Word (paragraph 5), but also for the saving understanding of those things as are revealed in the Word. The Spirit gives us inward illumination to savor and love the truths revealed in the Word.
There are some things which are not revealed in the Word concerning the circumstances of the worship of God or the government of the church, but are left to be ordered by the light of nature (i.e., common sense) and Christian prudence (wisdom). These are things like the time of worship on the Lord's Day, the type of building or place to worship, how long the service will be, beamer screen or not, or the finances of the church. These are things which the Scripture does not directly or indirectly speak about but are left to Christian wisdom and common sense. Nonetheless, the general rules of the Word are still to be observed in these matters. These are not to be disconnected from the Word just because they are not directly addressed by the Word. See chapter 22 about the elements and circumstances of worship.
The Sufficiency of Scripture
To say that Scripture is sufficient is not to say that it speaks on every topic imaginable or that it tells us everything that we should do and everything which we should not. Rather, the sufficiency of Scripture is defined as Scripture containing everything necessary that God wanted us to know about salvation, faith, and the walk of obedience. Whatever God had deemed necessary for His people to know, He has written for our benefit in Scripture. The primary passage in Scripture which teaches the sufficiency of Scripture is 2 Timothy 3:16:
2Tim. 3:16-17 All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, 17 that the man of God may be complete, equipped for every good work.
Here, the Apostle Paul gives us a great and necessary-to-know description of Holy Writ. The Scriptures, all of it, is profitable for teaching us the will of God; for reproving and criticizing us and our actions, because in them God has revealed His perfect Law of rig...