The Lutherkirche in Bad Harzburg was built between 1901 and 1903 in the Gothic Revival style, at a time when Bad Harzburg was developing into an important spa town. The church interior, with its favourable acoustics, provides an excellent setting for the large Romantic organ on the west gallery.

The original organ was built in 1903 by Wilhelm Sauer of Frankfurt (Oder) as Opus 891 and was donated by the König family. It originally had two manuals, pedal and 29 stops on pneumatic cone chests. During the 20th century the organ underwent several rebuilds, tonal alterations and eventually an electrification of the action, while a substantial amount of the historic Sauer pipework survived.

In the 1990s the parish decided not merely to overhaul the existing instrument but to reconstruct its Romantic character. From 1997 onward Christian Scheffler of Frankfurt (Oder), a specialist in historic Sauer organs, developed a concept that restored the symphonic Romantic tonal ideal while adding a third manual division. The first stage was completed in 1998, and the reconstructed instrument was inaugurated on the first Sunday of Advent in 2001.

Today the Sauer/Scheffler organ has three manuals and pedal with a total of 40 stops. It once again uses pneumatic cone chests and combines restored historic Sauer material with components and stops carefully reconstructed in the historic style. Its sound is characterised by warm fundamental tone, finely graded string and flute colours and an effective Romantic crescendo. This makes the instrument particularly well suited to German late-Romantic repertoire, including the music of Max Reger, Siegfried Karg-Elert and Julius Reubke.