Jesus calls God “Father,” and teaches us to do the same (see: the Lord’s prayer). This means that the basic defining relationship between us and God is that of a Father and his children. Which is the same relationship God had with the children of Israel. This means that what was relationally true of the people in the OT is also true of us. How God interacts with them is how God interacts with us. How God feels about them is how God feel about us.
It is also true that we often respond just as they did. We read the NT and wonder how the disciples could be so thick-headed, how the Pharisees could be so blinded by their religion. We read the OT and we wonder how the Israelities could so easily run back to idolatry, how even someone like David could turn and do something so evil as to steal a man’s wife and then have him murdered. But we are just like all of them. We are the thick-headed disciples. We are the blinded-by-religion Pharisees. We are the faithless Israelites worshipping a golden cow, with the memory of the parted sea still fresh in our minds. We are David, whose lust can overwhelm us, even if we are a man after God’s own heart.
The Bible is full of human weakness and failings. The more we can identify with that and see it in ourselves, the more we will have an accurate picture of ourselves and our sinfulness. The Bible is also full of the love, mercy, and grace of a Father God who knows all this and loves His children anyway. If we can learn to see ourselves in all those relationships between God and humans in the Bible, we will get, not only a more accurate picture of ourselves, but a more accurate picture of oursevles as God sees us, as a Father who loves His children.