4 Trust in the Lord forever, for the Lord, the Lord, is the Rock eternal. 5 He humbles those who dwell on high, he lays the lofty city low; he levels it to the ground and casts it down to the dust.
This verse exhorts us to trust in God, for He is powerful (the “Rock eternal,” meaning security and strength), and He alone has the power to humble us and take apart the godless things we build up for ourselves. (The “lofty city” referred to in verse 5 can reference Babylon, Jerusalem, Tyre, or even Rome, but the meaning is the same, regardless: those things we build up to be so “impenetrable” and “strong” can still be taken down at a word from God.) Whatever we worship in place of God, like money, power, technology, or knowledge, will always be leveled to dust, to show us that they are not what we should be focusing on.
But the enemies that rise up against us and the trials we endure can also be defeated at a word from God. He is trustworthy because He never deserts us, as the rest of chapter 26 of Isaiah, a song of praise, attests. When we are faithful to His Word, He is faithful to His promises for us; when we are unfaithful to His Word, He disciplines us, but still never leaves us utterly alone. God is the truest friend we will ever have, but He is not like an earthly “buddy”–He is God, almighty and sovereign.