Before going too far, we should understand the Bible used in Jesus’ time. The Old Testament was not a book like we use today, but consisted of a number of scrolls, grouped as the Law, the Prophets and the Writings. The Law consisted of the first five books of the Bible, from Genesis to Deuteronomy, the books written by Moses. The Prophets were the scrolls containing Joshua, Judges, 1 and 2 Samuel, 1 and 2 Kings, Isaiah, Jeremiah, Ezekiel and the scroll containing the minor prophets, from Hosea to Malachi. The Writings consisted of the Psalms, Proverbs, Job, Song of Solomon, Ruth, Lamentations, Ecclesiastes, Esther, Daniel, Ezra, Nehemiah, 1 and 2 Chronicles. This group was sometimes called the Psalms as that was the first and the largest scroll in this group.
Thus when New Testament writers refer to the Law, they are referring to that whole group of scrolls, not only to the part of it which contained laws. Likewise, when referring to the Prophets, they meant all the scrolls in that group, including those which we consider historical writings. Since all the writers of Scripture were considered prophets, The Law and the Prophets included the whole Old Testament. Jesus once said: “These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me,” meaning the whole Old Testament. The quotation is found in Luke 24:44.
One more historical fact needs to be mentioned: these scrolls had all been translated into Greek about 200 years before Jesus’ day. All the quotations from the Old Testament that are found in the New Testament come from this Greek translation. This explains some differences in names: Eli for Elijah and Elias for Elisha. In addition, Jesus is the same name as Joshua, Mary the same as Miriam and James the same as Jacob.
The apostles clearly understood the whole of the Old Testament writings to be divinely inspired. “For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost” (2 Peter 1:21). “For whatsoever things were written aforetime were written for our learning, that we through patience and comfort of the scriptures might have hope” (Romans 15:4). “All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness” (2 Timothy 3:16).
The Word of God is eternal and unchangeable. “Ye shall not add unto the word which I command you, neither shall ye diminish ought from it, that ye may keep the commandments of the LORD your God which I command you” (Deuteronomy 4:2). “ For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book” (Revelation 22:18-19).
“For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled” (Matthew 5:18). “Heaven and earth shall pass away, but my words shall not pass away” (Matthew 24:35).
Parts of the Bible can be understood by non Christians, but to truly understand it, one must have the Holy Spirit. “Which things also we speak, not in the words which man’s wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual. But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned” (1 Corinthians 2:13-14). “But if our gospel be hid, it is hid to them that are lost” (2 Corinthians 4:3).
One verse written by the Apostle Paul has given rise to the idea that the Bible is all a jumble and it is up to us to put things together in the proper order: “Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth” (2 Timothy 2:15). The Apostle Paul was not telling us that the Bible is like a jigsaw puzzle and we need to puzzle out what piece goes where. What he is actually saying is that we should handle the truth honestly and correctly. The Apostle Peter gives a corrective for the modern misinterpretation of Paul: “As also in all his [Paul’s] epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction” (2 Peter 3:16). Peter uses the word wrest, which means to twist, or tear apart. Also note that Peter is already considering the epistles of Paul to be part of the Scriptures.
Peter also writes: “Knowing this first, that no prophecy of the scripture is of any private interpretation” (2 Peter 1:20). Differences in interpretation of the Scriptures are not the fault of the Holy Spirit, who inspired the writers and who will also inspire our understanding of what was written.