ENThe authors present the results of their analyses of two financial registers from the years 1668 and 1674 belonging to the Lithuanian Evangelical Reformed Church (Jednota Litewska). The documents among others include records of donations on behalf of the confessional community, endowments for specific churches and loans given by the Lithuanian Evangelical Reformed Church to its believers. The authors focus on such issues as ways of accepting the loans by borrowers as well as the struggle of the loaners to get their loaned money payed back. They also characterize individual partners of the Lithuanian Evangelical Reformed Church in its credit activities stressing the ambiguous role many of them played, including the Radziwills who gave a political protection to the Calvinist Church while at the same time they taking advantage of their position as its creditors.