Martin Luther’s famous hymn is a sermon in song based on Psalm 46. Likely penned during the “disastrous year” of 1527, the Psalm provided great assurance during times of Luther’s darkest moments of trial and testing. While we live in a fallen world and must endure a "flood of mortal ills," our God is a mighty fortress in which we find refuge. He is our able and willing helper, a "bulwark never failing."