Grant Osborne talks about the "Hermeneutical Spiral," which just means that as you understand the details in a book it shapes your understanding of the big picture, and as you better understand the big picture of a book you better understand the details, and so these two work back and forth and "spiral" toward the actual meaning of the text. Little stories like the tower of Babel and David and Goliath should be taken into account for what the Pentateuch or the Book of Samuel as a whole mean, and visa versa.
The Bible is not the only text that works this way. I completed an English minor during undergrad at Multnomah, and the striking thing to me was that literature across the board is written like this. When an author sets about to put together a book, he has a big idea in mind. The biblical authors were really great authors. They were master craftsmen, and their skills mainly consisted in being able to put together what could otherwise simply be nice moral stories in such a way that creates one coherent theme. The Pentateuch or the Book of Samuel were not written like modern novels are written. Stories like the flood and Babel had probably been passed down orally; there may have even been written sources which he gathered and arranged. So when Moses wrote the Pentateuch, he did not write it from start to finish. His skill in "writing" the Pentateuch consisted of putting together stories and laws in a way that relate to each other. The biblical authors of many of these historical narratives were perhaps "making books" (Ecc 12:12) rather than writing books.
So it is extremely important to read the legal codes in the Pentateuch for instance in view of the fact that 60 chapters of narratives and stories (stories that teach us about the importance of living by faith) precede these laws. It is likewise important to recognize that the story of David is placed within a book that begins saying, "Yahweh will judge the ends of the earth; he will give strength to his king and exalt the power of his Christ (anointed)" (1 Sam 1:10) and ends saying, "Great salvation he brings to his king, and shows steadfast love to his Christ, to David and his offspring forever" (2 Sam 22:51).
If you read through Samuel, it becomes quite clear that Israel is foolish for trusting in a king who looks good like the other kings. They wanted "a king to judge us like all the nations" (1 Sam 8:6) and Saul was "a handsome young man. There was not a man among the people of Israel more handsome than he. From his shoulders upward he was taller than any of the people" (1 Sam 9:2). Israel trusted Saul because he looked like he could compete against the Gentile kings. Yet "man looks on the outward appearance, but Yahweh looks on the heart. (1 Sam 16:7).
So the story of David and Goliath is in a book with an author who is very concerned to demonstrate that the best king for Israel is not the one who looks good and strong on the outside, but one who trusts in Yahweh. What kind of King should Israel trust in? What will the Messiah, the Anointed One, the Christ, the one who will finally totally save Israel from their enemies - what will he look like? He looks like David, the one who had faith in Yahweh and defeated Goliath.
This is reading the story of David and Goliath in context. The Book of Samuel is not an anthology of short stories in Israel's history. The author is a very good author. He is strategic in the way he crafts his work. These stories had probably been told for centuries. His skill is not in coming up with nice moral stories. His skill is in how he arranges them and crafts them in a way that tells one big story. This is why paying attention to the context of the big idea of a book is very crucial. The story of David and Goliath was simply not meant to be read alone. There were no chapter breaks; this was all one book about the promised king of Israel, the promised Messiah who would save Israel.
The story of David and Goliath is about the coming Christ who would save Israel. This is perhaps not obvious to modern readers because we live in a flannel graph Christian culture which tends to pull these stories out of the context of their books and retell them as nice moral stories.
To conclude, I will mention that it is on the hand crucial that we see that moral aspect of these stories. Christians are called to follow Jesus, to be like Jesus. We are all called to faith in the Father. We are called to trust in God and find our strength in him as we face the giants in our lives. But if we miss Jesus in these stories, I think that Jesus might accuse us of what he accused the pharisees: "You search the Scriptures for you think that in them you have eternal life; and it is they that bear witness about me" (John 5:39). He also explains to his disciples "that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled" (Luke 24:44).
This isn't a mystical Holy Spirit code we imposing upon the Hebrew Bible. It is simply acknowledging that the Hebrew Bible is a book about the coming Messiah.
