Mit seinem Geist is based on the choral Ein' feste Burg ist unser Gott by Martin Luther and Psalm 46, and develops a set of eight variations. The opening movement bursts in with a toccata-like texture with overflowing joy. Variation II is an expressive ornamentation of the melody in the treble. Variation III is a harmonisation of the choral accompanied by a perpetuum mobile in the left hand, symbolising the stream evoked in Ps. 46, 5. The image of the stream is recalled in variation IV, with a gracefully flowing development of the melody. Variation V is a peaceful meditation with the melody in the left hand. By contrast the very lively variation VI figures, with its abundant arpeggios, an inextinguishable strong stream; it culminates on a bright carillon radiant with joy. Variation VII is a contemplative choral harmonisation. The conclusive variation recalls the opening with its cheerful and dancing character.