1748 portrait of Bach, showing him holding a copy of the six-part canon BWV 1076
See Wikipedia for an extensive introduction to Bach's life and music
See this issue of Christian History Magazine for its several articles on 'The Gospel According to J.S. Bach'.
For more on the Hymns of Our Faith, see our Library Guide on Music and the Hymns of Faith
While not a 'theologian', Bach is included in this series of bibliographies as one whose music has had significant influence on a host of theologians, from his day and onward. (e.g. Albert Schweitzer/AS2; Bonhoeffer; Jaroslav Pelikan; Lutheran Theologians in general)
Select Full-Text Articles from ATLA Religion on the Theology of Bach's Music: Theology in Bach's Music--ATLA Religion Database
Johann Sebastian Bach as Musician and Atonement Theologian, by Paul Copan in The Worldview Bulletin Newsletter; Bach: A Theologian at the Workplace, by J. Camire