This may be a question you’ve never asked before but it’s extremely important to understanding Jesus, the Old Testament, and God’s covenantal nature.
Some people will argue that Jesus didn’t see the Old Testament scripture as fully inspired by God. In fact, they will try to argue that our evangelical belief that Jesus saw scripture as God’s word is imposing too much into the gospel accounts of Jesus. To be fair, Jesus doesn’t come out as clearly as Paul or Peter does in his view of scripture. But a careful study of the gospels will show us that Jesus does believe all of the Old Testament scripture is God’s very word.
What are the dangers of seeing scripture as mostly man-made?
The danger of believing scripture was primarily written by man, is that it can then be wrong since to be man is to err. We would devolve our view of God’s word to something that sometimes is breathed out by God and sometimes not. Truly what is at the heart of this way of reading the Bible, is trying to read the Bible’s “archaic” views on certain cultural beliefs, and “lift it up” into the modern era. In other words, because what is going on around us — culturally — seems uncomfortable to the average person, we are going to decide what parts are good for us to believe came from God, and what parts were “those old testament writers doing their best thousands of years ago.”
Inevitably what this will do, is allow us to change scripture's intended meaning to whatever we need it to be so we don’t offend the current cultural flavor.
Did Jesus believe the Old Testament prophecies were about himself?
Right around Christmas time, you will start to hear all of the amazing prophecies about Jesus concerning his birth life, and death. But did those prophets really know what they were saying? The short answer is no. When Isaiah said:
4 Surely he has borne our griefs
and carried our sorrows;
yet we esteemed him stricken,
smitten by God, and afflicted.
5 But he was pierced for our transgressions;
he was crushed for our iniquities;
upon him was the chastisement that brought us peace,
and with his wounds we are healed.
6 All we like sheep have gone astray;
we have turned—every one—to his own way;
and the LORD has laid on him
the iniquity of us all. 
Surely he had no idea of the crucifixion that would come. So, how can we understand scripture differently than the original author? We can’t understand it differently, but we can understand it more fully. This is the idea — some theologians call — sensus plenior. In his book Canon, Covenant, and Christology, Matthew Barrett — the associate professor of Christian Theology at Midwestern Baptist Theological Seminary — defines sensus plenior like this, “when a [it] is first revealed in scripture, it is a t this point — its conception — that the human author’s purview is the most limited, not knowing all the intentions the divine author has in mind.” When Isaiah wrote this prophecy he could see dimly what we see clearly. He knew the Messiah would suffer, but how exactly he didn't know. Yet he was still very correct about the nature of his suffering.
What this idea shows us is that God’s nature and his revelation must be understood in light of all of scripture, rather than a brief moment of the historical author’s understanding. In other words, God prophesied using humans in one time, so that humans in another time could recognize the prophecy in its fullest sense.
It comes down to the question of how can we interpret the Bible. Is the only justifiable rating of scripture one that only sees the human author’s intent, or are we able to see Scripture as written by one divine author who knew the full scope of redemptive history? Did Jesus believe all scripture was about him?
Jesus saw what the prophets couldn’t, by living into the promises they made centuries before he came to earth. By his recognition and living into these prophecies, Jesus is affirming the Old Testament scripture as the very word of God and not only of mere men. This is what we call the scripture’s plural authorship. This means that all scripture is written by both human and divine authors.
Jesus affirms Israel’s view of Old Testament scripture
Jesus was Jewish, while it may seem obvious. But he came into a world where — even his enemies within Judaism — saw scripture as God-breathed. This is most clearly seen by looking at the covenants of the Old Testament. Matthew Barrett, says “God spoke a saving word in and through the cutting of covenants with his people, covenants that not only explained Israel’s Genesis but maintained their relationship with Yahweh as his chosen people.” God's relationship with Israel was in the form of written words. Not merely words that he agreed with but works that came from his mouth. The fact that Jesus fulfills the covenant shows us that he sees, recognizes and affirms the reality that the covenants in the Old Testament are not just a man’s words, but the precious words of the God of the universe. It is maybe clearest that the truthfulness and beauty of the Old Testament scriptures are upheld in the fulfillment of God’s covenant promises.
The clearest passages
You are probably familiar with the passage in Luke 24:13-27. This is the story of Jesus revealing himself to two disciples after his resurrection. As he makes known to the two disciples who he is Luke goes on to write this memorable verse, “And beginning with Moses and all the Prophets, he interpreted to them in all the Scriptures the things concerning himself.”
Jesus shows the disciples that all of the Old Testament scriptures were pointing toward himself.
17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. 18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. 19 Therefore whoever relaxes one of the least of these commandments and teaches others to do the same will be called least in the kingdom of heaven, but whoever does them and teaches them will be called great in the kingdom of heaven.
Here in Matthew 5:17-19, Jesus gives one of the clearest pictures of how he views scripture. Jesus loves the scriptures, not as wisdom from men, but as the word of God. In fact, the reality of Christmas — or God becoming flesh — is an inditement against worldly wisdom. Jesus couldn’t have seen scripture as merely from men, the incarnation is a testament against it.
Jesus’ actions show that he loves the Old Testament scripture. In his commentary on Matthew, theologian, and professor, D.A. Carson says, “that Jesus fulfills the Law and the Prophets in that they point to him, and he is their fulfillment. The antithesis is not between ‘abolish’ and 'keep’ but between ‘abolish’ and ‘fulfill.’ ‘For Matthew, then, it is not the question of Jesus’ relation to the law that is in doubt but rather its relation to him!’”
Jesus’ obedience to the law confirms that he believes the law was God’s word. If Jesus didn’t believe that — and is still God himself — he would have had no need to keep them. If they weren’t authoritative, Jesus would have had no desire to be obedient, but we see the exact opposite. Jesus was obedient, “And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross.”
Jesus was the word of God. His closest friends on earth attested to this. Jesus loved the scripture because he embodied it. Have confidence that Jesus not only believed that the Old Testament scriptures were breathed out by God, but he loved, cherished, and was obedient to them. Therefore we — as Christians — ought to love, trust, and obey God’s holy word too.
 The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Is 53:4–6.  The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Lk 24:27.  The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Mt 5:17–19.  D. A. Carson, “Matthew,” in The Expositor’s Bible Commentary: Matthew, Mark, Luke, ed. Frank E. Gaebelein, vol. 8 (Grand Rapids, MI: Zondervan Publishing House, 1984), 143–144.  The Holy Bible: English Standard Version (Wheaton, IL: Crossway Bibles, 2016), Php 2:8.  John Chrysostom, “Homilies of St. John Chrysostom, Archbishop of Constantinople on the Gospel according to St. Matthew,” in Saint Chrysostom: Homilies on the Gospel of Saint Matthew, ed. Philip Schaff, trans. George Prevost and M. B. Riddle, vol. 10, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, First Series (New York: Christian Literature Company, 1888), 104–105.