Jaknavičius prepared and published a book about the Polish and Lithuanian gospels for sermons (Polish: Ewangelie polskie y litewskie, Lithuanian: Lenkiškos ir lietuviškos evangelijos) which was republished 40 times in the 17th-19th centuries due to their popularity.[1][5] The Ewangelie polskie y litewskie was written and published in Polish and Lithuanian languages.[6] The oldest surviving version of the Ewangelie polskie y litewskie is from 1647 and was recognized by UNESCO (currently preserved at the Kaunas University of Technology).[1][7][8]
Jaknavičius also contributed to the 2nd edition (1631) of Konstantinas Sirvydas' dictionary Dictionarium Trium Lingvarum in usum Studiosæ Iuventutis.[1]