What led Luther toward this Psalm? He used it for his classic hymn - "refuge" can be a shield and "strength" a weapon. How is God present, as a refuge and strength, among His people? He is present in His Word; though the mountains may "give way" (connoting a changing world), His Word will not pass away. The LORD is steadfast, immovable, faithful. The Word is also "a river" nourishing and restoring us.God speaks - and things change. "It is finished." "Peace, be still." One little word can fell the tempter and accuser. Luther took refuge in this fact when in fear. He stood on Christ alone, and so do we! As a more contemporary example, the forerunners of the LCMS were in the midst of distressing changes, being uprooted into America, but they clung to the faith. This yielded Walther's Law and Gospel, Pieper's Dogmatics, Maier's "Lutheran Hour," Hoffman's preaching.What remains? God's voice. Lutherans hold to this, even as the world turmoils, demographics change, people fall away. God still speaks through His people, the Church. Therefore the Reformation is a present reality, not merely church history. God is with us. Who can stand against us?
Soli Deo gloria.