Listen to A Mighty Fortress Is Our God online. A Mighty Fortress Is Our God is an Unknown language song and is sung by The Chestnut Brass Company and Martin Luther. A Mighty Fortress Is Our God, from the album A Heritage of Hymns - Classic Recordings of the Great Songs of Faith and Inspiration, was released in the year 2006. The duration of the song is 2:42. Download Unknown songs online from JioSaavn.