After his Jesuit training in Lithuania – philosophy (1747–50) and theology (1753–57) at Academy of Vilnius – Czerniewicz taught grammar and poetry in the Kražiai College (1750–53) before being called to Rome where he was secretary for the Polish Assistancy of the Society of Jesus (1759–68).
The brief of Clement XIV suppressing the Society (July 1773) could not be promulgated in the Jesuit houses of the Russian Empire, as the Czarina Catherina the II of Russia, a non-Catholic, strictly forbade it.
As this was rather unofficial and he had no legal authority over the Jesuits, Czerniewicz requested the local bishop (in charge of religious affairs) and Catherine II permission to call a Regional Congregation to elect a vicar general of the society.
The opening of the novitiate and then the election of a vicar general created a diplomatic crisis between Russia and the Bourbon's courts in Europe, but Catherine defended "her Jesuits" with the silent approval of Pius VI.
Faithful to the Constitutions of Saint Ignatius, Czerniewicz quietly prepared the rebirth of the society, conducting a correspondence with many ex-Jesuits in a number of European countries and keeping them informed of Russian developments.