“If Thou But Trust in God to Guide Thee” (“Wer nur den lieben Gott lässt walten”) is the most well-known of the texts and tunes by the German poet and hymn-writer Georg Neumark (1621-1681).
The tune, one of the most venerable in Protestant hymnody, was used by J.S. Bach in several works, most notably in the cantata “Wer nur den lieben Gott lässt walten” (BWV 93). Felix Mendelssohn also adapted the text and melody as a cantata, and Johannes Brahms used it as a theme at various points in his Ein Deutsches Requiem (German Requiem).
In this arrangement, an outline of the tune is presented in 4/4 time as an introduction, followed by three verses in differing orchestrations and harmonizations in the tune’s typical 3/4 meter, and concluding in a fashion similar to the introduction.