This is one of the songs of Zion that sings of God's protection to be found there-not because the place is magic, but because of God's presence. This psalm was the basis for Martin Luther's Reformation hymn, "A Mighty Fortress Is Our God."
All things change, recognizes the psalmist; worse, all things are inherently unstable--including the earth itself, its mountains and seas, and the nations and peoples on the earth (vv. 1-7). Only God is a stable refuge, and that refrain serves as an inclusio surrounding this section of the psalm. It shows up also in the middle of the stanza, just as God "is in the midst of the city" (v. 5). Earthquakes and floods may inform the psalmist's view here, but the trouble goes beyond those events. Particular disasters are signs of the eruption of chaos that threatens God's creation and puts everything in danger.
The careful structure of the stanza is itself a poetic hedge against chaos:
A God is our refuge and strength
B The earth changes
C God is in the midst of the city, which therefore shall not be moved
B' The nations are in an uproar
A' God is our refuge
The next stanza is a hymn to this strong and stable God. Most important, God makes wars cease, which, of course, will take care of the "uproar" of the nations in v. 6. The psalm looks forward to God's stabilized world, which will be a world of peace; all weapons will be destroyed (see also the similar prophecy about Zion in Isaiah 2:1-4). The worshiping community then hears a word direct from God (announced probably by a priest), assuring them that God's strength and God's promise is for them. The control of chaos is beyond human ability, so the counsel is simply, "Be still, and know that I am God!" The song ends by returning to the theme and refrain: "The Lord of hosts is with us; the God of Jacob is our refuge."
Like all promises, this one, too, could be misunderstood, as though Zion were invulnerable because God's presence could be taken for granted. Eventually, the prophets had to denounce such thinking, especially Jeremiah with his insistence that people could not simply chant the mantra "The temple of the Lord, the temple of the Lord, the temple of the Lord" and think nothing bad could happen to them (Jeremiah 7:4). No aspect of biblical religion can ever be used as a talisman or good-luck charm. God's presence and God's security is found among those who repent, change their ways, and do justice (Jeremiah 7:5-7).
1 God is our refuge and strength,
a very present* help in trouble.
2 Therefore we will not fear, though the earth should change,
though the mountains shake in the heart of the sea;
3 though its waters roar and foam,
though the mountains tremble with its tumult.
4 There is a river whose streams make glad the city of God,
the holy habitation of the Most High.
5 God is in the midst of the city;* it shall not be moved;
God will help it when the morning dawns.
6 The nations are in an uproar, the kingdoms totter;
he utters his voice, the earth melts.
7 The Lord of hosts is with us;
the God of Jacob is our refuge.*
8 Come, behold the works of the Lord;
see what desolations he has brought on the earth.
9 He makes wars cease to the end of the earth;
he breaks the bow, and shatters the spear;
he burns the shields with fire.
10 Be still, and know that I am God!
I am exalted among the nations,
I am exalted in the earth.
11 The Lord of hosts is with us;
the God of Jacob is our refuge.*
New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org