What Jesus Affirmed about the Old Testament.

The New Testament was not written until after Jesus ascended into heaven. Hence, his statements about the Bible refer to the Old Testament. But what Jesus confirmed for the Old Testament, he also promised for the New Testament.

Jesus affirmed the divine authority of the Old Testament.

Jesus and his disciples used the phrase “it is written” more than ninety times. It is usually in the perfect tense, meaning, “it was written in the past and it still stands as the written Word of God.” Often Jesus used in the sense of “this is the last word on the topic. The discussion is over.” Such is the case when Jesus resisted the temptation of the Devil.

But he answered and said, It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God. . . . Jesus said unto him, It is written again, Thou shalt not tempt the Lord thy God. Jesus said to him, It is again written, Thou shalt not tempt [the] Lord thy God. . . . Then saith Jesus unto him, Get thee hence, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve. [Matt. 4:4 , 7 , 10 , emphasis added] This use demonstrates that Jesus believed the Bible to have final and divine authority.

Jesus affirmed the Old Testament to be imperishable.

“Think not that I am come to destroy the law or the prophets: I am not come to destroy, to fulfill. Think not that I am come to make void the law or the prophets. 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” ( Matt. 5:17–18 ). Jesus believed the Old Testament to be the imperishable Word of the eternal God.

Jesus affirmed the Old Testament to be inspired.

Although Jesus never used the word inspiration, he did use its equivalent. To the Pharisees’ question, he retorted: “How is it then that David, speaking by the Spirit , calls him ‘Lord’?” ( Matt. 22:43 , emphasis added). Indeed, David himself said of his own words, “The Spirit of the LORD spoke through me; his word was on my tongue” ( 2 Sam. 23:2 ). This is precisely what is meant by inspiration.

Jesus affirmed that the Bible is unbreakable.

The word infallible is not used in the New Testament, but a close cousin is— unbreakable. Jesus said, “If he called them gods, unto whom the word of God came, and the scripture cannot be broken ” ( John 10:35 ). Indeed, three powerful words describe the Old Testament in this short passage: “law” (vs. 34 ), “word of God,” and “unbreakable.” Thus, Jesus believed that the Old Testament was the unbreakable law of God.

Jesus affirmed the Old Testament is the Word of God.

Jesus regarded the Bible as the “Word of God.” He insisted elsewhere that it contained the “commandment of God” ( Matt 15:3 , 6 ). The same truth is implied in his reference to its indestructibility in Matthew 5:17–18 . Elsewhere, Jesus’ disciples call it “the oracles of God” ( Rom. 3:2 ; Heb. 5:12 ).

Jesus ascribed ultimate supremacy to the Old Testament.

Jesus often asserted the ultimate authority and supremacy of the Old Testament over all human teaching or “tradition.” He said to the Jews: “Why do you break the command of God for the sake of your tradition? . . . Thus you nullify the word of God for the sake of your tradition” ( Matt. 15:3 , 6 ). Jesus believed that the Bible alone has supreme authority when even the most revered of all human teachings conflict with it. Scripture alone is God’s supreme written authority.

Jesus affirmed the inerrancy of the Old Testament.

Inerrancy means without error. That concept is found in Jesus’ answer to the Sadducees, a sect who denied the divine inspiration of the Old Testament, “Ye do err, not knowing the scriptures [which do not err], nor the power of God” ( Matt. 22:29 KJV ). In his high priestly prayer, Jesus affirmed the total truthfulness of Scripture, saying to the Father, “Sanctify them through thy truth: thy word is truth” ( John 17:17 KJV ).

Jesus affirmed the historical reliability of the Old Testament.

Jesus affirmed as historically true some of the most disputed passages of the Old Testament, including the creation of Adam and Eve ( Matt. 19:4–5 ), the miracle about Jonah in the great fish, and destruction of the world by a flood in the days of Noah. Of the latter, Jesus declared: “As it was in the days of Noah, so it will be at the coming of the Son of Man. For in the days before the flood, people were eating and drinking, marrying and giving in marriage, up to the day Noah entered the ark” ( Matt. 24:37–38 ). Jesus affirmed that Jonah was really swallowed by a great fish for three days and three nights: “For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth” ( Matt. 12:40 ). Jesus also spoke of the  laying of Abel ( 1 John 3:12 ), Abraham, Isaac, and Jacob ( Matt. 8:11), the miracles of Elijah (James 5:17 ), and many other Old Testament persons and events as historically true, including Moses, Isaiah, David, and Solomon ( Matt. 12:42 ), and Daniel the prophet ( Matt. 24:15 ). He affirmed the historical reliability of major disputed passages of the Old Testament. Both the manner in which these events are cited, the authority they are given, and the basis they form for major teachings Jesus gave about his life, death, and resurrection reveals that he understood these events as historical.

Jesus affirmed the scientific accuracy of the Old Testament.

The most scientifically disputed chapters of the Bible are the first eleven. Yet Jesus affirmed the account throughout this section of Genesis. He unflinchingly bases his moral teaching about marriage on the literal truth of the creation of Adam and Eve. He said to the Pharisees, “Haven’t you read,” he replied, “that at the beginning the Creator ‘made them male and female,’ and said, ‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh’?” ( Matt. 19:4–5 ). After speaking to Nicodemus, the ruler of the Jews, about physical earthly things like birth and wind, Jesus declared: “I have spoken to you of earthly things and you do not believe; how then will you believe if I speak of heavenly things?” ( John 3:12 ). In short, Jesus said that, unless one could believe him when he spoke of empirical scientific matters, then they should not believe him when he speaks of heavenly matters— revealing that he considered them inseparable.

What Jesus promised about the New Testament.

Jesus not only affirmed the divine authority and infallibility of the Old Testament, he also promised the same for the New Testament. And his apostles and New Testament prophets claimed for their writings what Jesus had promised them. Jesus said the Holy Spirit would teach “all truth.” Jesus promised that “the Comforter, [which is] the Holy Ghost, whom the Father will send in my name, he shall teach you all things , and bring all things to your remembrance, whatsoever I have said unto you.” He added, “Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, [that] shall he speak” ( John 14:26 ; 16:13 ,emphasis added). This promise was fulfilled when they spoke and later recorded (in the New Testament) everything Jesus had taught them.

The apostles claimed this divine authority Jesus gave them.

Not only did Jesus promise his disciples divine authority in what they wrote, but the apostles claimed this authority for their writings. John said, “these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name” ( John 20:31 ). He added, “That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life” ( 1 John 1:1 ). Again, he said, “Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world. . . . They are of the world: therefore speak they of the world, and the world heareth them. We are of God: he that knoweth God heareth us; he that is not of God heareth not us. Hereby know we the spirit of truth, and the spirit of error” ( 1 John 4:1 , 5–6 ). 

Likewise, the apostle Peter acknowledged all Paul’s writing as “Scripture” ( 2 Peter 3:15–16 ; cf. 2 Tim. 3:15–16 ), saying, “And account [that] the longsuffering of our Lord [is] salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you. As also in all [his] 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.”

The New Testament is the record of apostolic teaching.

But the New Testament is the only authentic record of apostolic teachings which we have. Each book was written by an apostle or New Testament prophet ( Eph. 2:20 ; 3:3–5 ). 

Therefore, the New Testament is the “all truth” Jesus promised.

From the fact that Jesus promised to lead his disciples into “all truth,” and they both claimed this promise and recorded this truth in the New Testament, we may conclude that Jesus’ promise was finally fulfilled in the inspired New Testament. In this way, Jesus directly confirmed the inspiration and divine authority of the Old Testament and promised the same, indirectly, for the New Testament. Therefore, if Christ is the Son of God, then both the Old Testament and the New Testament are the Word of God.

Source: Bakers Encyclopedia of Christian Apologetics, Pg. 59-62.