The basic premise in this chapter is the Lord telling the people that if you do what you are supposed to do then I will reward you. If you do not do what you are supposed to do then you will be punished. Jesus comes at it with a bit of a different perspective when he says in Matthew 5:45: that the rain will fall on the good and the bad. That has always been my theological approach. I know that if we make bad decisions and we sin consistently in a way that is unremorseful then we are going to have to deal with the issues that come around because of those decisions.
That is a bit different from saying that if we sin then God is going to punish us. That would be a God that is definitely more hands on, but not really a God that I see as being consistent in the New Testament. I agree that we do see that message promulgated in the Old Testament. If you obey me then I will give you victory in battle, I will bless your crops, I will bless your families. If you disobey me then I will abandon you as you have abandoned me. This kind of direct correlation between the grace of God and the obedience of humanity would exclude the act of grace on the cross.
Remember we read Paul tell us that even while we were yet sinners, even then God died on the cross and was involved in the most redemptive act, and undeserved act on the part of the receivers, ever known in human history. God treats us as we don’t deserve is a strong underlying theme in the New Testament. But that breaks pretty directly from what we read here in the Old Testament.