This final verse, completes the description of the total destruction of evil in the world.
The strongholds, represent all things that people look to for their strength and for their security and for their power.
The princes, refer to all leaders, to all leadership, to all celebrities, to all that believe they are something or somebody in this world.
And in their final moments, they will see the true opposition, which is not of this world, but recognize that it is God through Jesus Christ, alone, whom they have been opposing all along.
The ensign, refers to the banner or standard or symbol. And in this case it refers to the entire concept of Christianity.
The fire of Zion, refers to the mountain of truth, or Bible doctrine.
The furnace in Jerusalem, refers the absolute peace and completeness and power of spiritual maturity, which originates from and resides in Jesus Christ.
All of history is centered around Jesus Christ.
Although people pursue their day-to-day life chasing after this priority or that priority, or this thing or that thing, or this plan or that plan, none of it has any value whatsoever when they lack a complete spiritual life.
While humanity plays tug-of-war with himself, within the environment of this earth, there is a greater conflict that exists outside this physical world. And it is that conflict that will decide everything, not mans many conflicts, which are petty in nature, by comparison.
To ignore the greater picture of reality and life, is to end up completely and totally destroyed.