If I thought the Bible was just another book, written by human authors and only containing various people's ideas about God, then I wouldn't bother to quote it or build my life on it. It would be like any other religious book: a collection of thoughts about God which might or might not be true.
But I am persuaded the Bible is more than that—that it is God's Word in written form, given to us so we can know Him and learn how He wants us to live. As a young preacher, I went through a period of doubt about the Bible, realizing that if it wasn't God's Word, then I didn't have a reliable message to give to people. But after a period of intense searching and struggle I came away convinced that the Bible is indeed God's Word, and "All Scripture is God-breathed" (2 Timothy 3:16).
One reason I came to accept the Bible as God's Word was because of what Jesus said about the Scriptures. Repeatedly He quoted them as the Word of God, and He declared that "Heaven and earth will pass away, but my words will never pass away" (Mark 13:31). If Jesus accepted the Scriptures as God's Word, shouldn't I also as His follower?
I urge you to get acquainted with the Bible personally, asking God to speak to you through its pages. Begin with one of the Gospels, for there you will meet the Bible's center—who is Jesus Christ. He will change you, as you open your life to Him.