One of the most difficult questions Christians grapple with is how do we know the Bible is from God and not the product of man? This is not a peripheral issue but goes to the heart of Christianity since the gospel is not a set of timeless moral principles but good news of something that happened in history.
The answer is that Jesus himself establishes the authority and truth of the Bible. First, he commissioned the writing of the New Testament through his apostles. Jesus appointed twelve apostles so that they might be with him and learn from him, and then to go out and proclaim his teaching (Mark 3:14-15). Jesus equipped the apostles with the Spirit, so that "he will teach you all things and bring to your remembrance all that I have said to you" (John 14:26). Acts speaks of the apostles as those "chosen by God as witnesses" of Christ (Acts 10:41).
And then second, Jesus everywhere affirms the Old Testament. So, for example, when Jesus cites Genesis that "man shall leave his father and mother and hold fast to his wife and they shall become one flesh," he states that this is from God (Matthew 19:4-6). Or when quoting from Psalm 110, Jesus identifies the Holy Spirit as the ultimate source (Mark 12:36). Thus everywhere, Jesus positively affirmed the divine authorship of the Old Testament.
Ultimately, Scripture rests on the authority of Jesus. He is at the center of the story and the one who establishes its veracity.