In 1602 he published a Greek etymological dictionary. In his period at Berlin, he published Antichristus Romanus, an anti-papal work including the numerical formula identifying Vicarius Filii Dei, an alleged title of the Pope, reduced to its Roman numerals and summed to 666. Brady mentions a theory of Johann Christoph Wolf that Helwig had already published this observation in an anonymous work of 1600.
Such cryptograms were not uncommon; Brady comments on (from Richard Bernard's Key of Knowledge of 1617) the phrase Generalis Dei Vicarius in Terris likewise treated, and Thomas Beard’s 1625 permutation Vicarius Dei Generalis in Terris, perhaps influenced by Helwig. This became Vicarius Dei Generalis in Terris with Hezekiah Holland in 1650. But interest in Helwig’s formulation has outlasted the others.
- Allgemeine Deutsche Biographie
- David Brady, The Contribution of British Writers Between 1560 and 1830 to the Interpretation of Revelation 13.16-18 (1983), pp. 84-6.
- Antichristus Romanus, in proprio suo nomine, numerum illum Apocalypticum (DCLXVI) continente proditus (Wittenberg, 1612)