In some of the Psalms, there is a raw spirit of hatred that is hard to stomach. On way to deal with them is to ignore them. But, if we believe that the Bible is written for our learning, then what use can we make of them. We cannot either explain them away or decide that such hatred is good.
One thing is clear—they express a feeling that we know only too well. We may not express it as rawly as the psalmist does, but we all feel it. And, when we read them, we should consider our own feelings—do we feel the same thing?
There must be a reason for such hatred. We see the natural reaction of someone who has been harmed in some fundamental way.
Even so, the reaction, while natural, is profoundly wrong. You might say the Jews were not Christian. But, the OT is full of corrections to their hatred. And even if that is an excuse, you should be able to find similar expressions of hate in pagan literature. Lewis does not find any. Why? He posits it is because they had a stronger sense of what is right and wrong than the pagans did.