John Gill

Therefore will not we fear,...., The consideration of the Lord's being the refuge, strength, and help of his people, in all times of trouble and distress, has a great influence on their faith and confidence, and makes them intrepid and fearless in the midst of the greatest dangers: nor indeed have they any reason to be afraid of men or devils, since the Lord is on their side; nor should they indulge a slavish fear on any account whatever; though the earth be removed; or "changed" (u), as to its position or fruitfulness; or whatever changes, vicissitudes, and revolutions may be in the kingdoms, nations, and among the inhabitants of the earth, through wars and desolations made thereby; and though the mountains be carried into the midst of the sea; so the destruction of kingdoms, empires, and cities, is expressed by a like phrase; as of Babylon, Jer 51:25; and of the Roman and Pagan empire, Rev 6:12, and of the city of Rome, Rev 8:8. (u) "cum mutabit", Pagninus; "etiamsi permutarit", Vatalbulus; "si commutaret", Junius & Tremellius, Piscator; so Ainsworth.