Johann Flitner

Flitner, Johann, was born Nov. 1, 1618, at Suhl, Saxony, where his father was an ironmaster. After studying theology at Wittenberg, Jena, Leipzig, and Rostock, he became in 1644 precentor, and in 1646 diaconus at Grimmen, near Greifswald. On the outbreak of the first Prusso-Swedish war he was forced to flee to Stralsund, but returned to Grimmen in May, 1660. At the death of his senior in 1664, he ought, according to custom, to have been appointed town preacher, but was passed over not only then but also in 1673 and 1676, when the post again became vacant. The outbreak of the second Prusso-Swedish war, immediately after this third disappointment, forced him again to flee to Stralsund, where he died Jan. 7, 1678 (Koch, ii. 442-445; Mohnike's Hymnologia Forschungen, pt. ii., 1832, pp. 3-54). His hymns seem to have been written during his enforced leisure at Stralsund. They appeared, with melodies, entitled Suscitabulum Musicum, as pt v. of his Himlisches Lust-Gärtlein. Greifswald, 1661 (Hamburg Library).

The only one translation into English is:—
Ach was soil ich Sünder machen. [Lent]. The most popular of his hymns. Appeared 1661 as above, p. 462, in 7 stanzas of 6 lines, each stanzas ending "Meinen Jesum lass ich nicht" (see note on Krymann) and with the motto "Omnia si perdam, Jesum servare studebo!" Included in the Leipzig Vorrath, 1673, No. 1089, and recently in the Unverfälscher Liedersegen 1851, No. 357. The only translation in common use is:—.
What shall I a sinner do? A good translation, omitting stanza vi., as No. 110 in Miss Winkworth's Chorale Book for England, 1863.
Another translation is: “What to do in my condition," is the Supplement to German Psalmody, edition 1765, p. 48.

--John Julian, Dictionary of Hymnology (1907)