A Mighty Fortress was written by the great Reformer, Martin Luther. This song became the rally cry for those who would carry on the Reformation and to encourage those who were facing persecution by the Catholic church.
20 years ago I heard Steve Green sing this song a cappella and, if you can get over the 20 year old look and feel of the video, I found this for your encouragement. Even if this isn’t your “style” (and I can’t really say it’s mine) I just challenge you to hear the song sung with probably close to the same conviction with which it was written.