Let me begin with saying that I believe the Old Testament is fact. The stories literally happened and the prophecies, inspired by God, have or will come true. It is important for me to establish this because of what I am going to be saying.
As a Christian I tend to focus on the New Testament more than the Old Testament. This is natural. We follow Jesus Christ. Our ways are very different from Jewish ways. So I sometimes develop this view of the Old Testament that pretty much says its importance is in how it sets the stage for the New Testament. Though this is true, Old Testament scripture holds valuable lessons and insights into God's nature.
I am reading Isaiah right now. It is a very difficult book to understand. It is loaded with prophecy. Some of the prophecies concern past events, some concern current events during the time it was written and others concern future events. I think Isaiah had a sense of humor because he throws all these different prophecies together. One moment you are reading about something in the past and the next moment you are reading about a future event. To make it even more confusing sometimes Isaiah seems to be speaking about past, present and future all in one passage!!
So I don't pertain to know a whole lot about Isaiah, but I did find something interesting. Starting in chapter 5 verse 8 a section of "Ahs" begins. These sections are basically Isaiah saying "Look guys!! These are things you are doing that God hates." I don't care if it is the New or Old Testaments. We should take careful consideration when God acts against certain actions.
So what does Isaiah reveal about the kinds of attitudes and actions God is against. 5:8-10 reveals that God does not like greed. At the root of greed is selfishness and it usually leads to the hurting of other people. God hates it! 5:11-17 reveals that God does not like debauchery (excessive indulgence in sensual pleasures). Again, the core of debauchery is selfishness. When people go to excess they usually do it at the expense of someone else. 5:18-19 reveals that God does not like it when we are impatient with him (or don't believe in his full power). Such impatience is a sign that we are putting ourselves on God's throne. We are virtually saying that we know best. 5:20-21 reveals that God does not like sophistry. Sophistry is when we try to rely on our own wisdom and make fallacious arguments in an attempt to justify ungodly action. 5:22-24 reveals that God does not like self ambition disguised as concern/justice for others. I think of politicians when I read this. In essence we are speaking of hypocrisy. People act like they are concerned for others but in reality it is their own selves they are truly concerned with.
These are some of the things Israel was found at fault with. In reality, they are things we all struggle with. If God punished Israel for such things then we need to take note and listen. It is not about being afraid of punishment though. It is about pleasing God.
I would encourage you to take time and examine yourself against these. If there is cause for concern then there is a need to repent. God calls us to turn away from those things which are not pleasing to him. The Old Testament does indeed have value!!