After a little bit of pleasant poetry of praise, we get prophecies about the destruction of Babylon, Assyria, and the Philistines. Now, some might consider those to be properly fulfilled prophecies. So let's be generous for a moment and assume that all the specifics which were not fulfilled were poetic license. In that case, Isaiah was just predicting that kingdom he did not like would fall. Guess what, they did! As has pretty much every kingdom that existed at the time. Kingdoms rose and fell all the time back in those days. In other words, despite all of Isaiah's verbosity, the results come as no surprise to anyone. This is especially true given that there were probably about 200-300 years between the writing of the earliest strata of Isaiah and the fall of Babylon. Even in modern times, a lot of countries have risen and fallen in that amount of time.
Paul closes his letter. This statement is interesting:
Examine yourselves to see if your faith is genuine. Test yourselves. Surely you know that Jesus Christ is among you; if not, you have failed the test of genuine faith.This verse says, essentially, that if you have doubt, you have failed. I wonder how many people on the edge of losing their belief were pushed further because of this verse.
Psalms and Proverbs
Repeat! We already know not to move boundary stones.