The presented article concerns the issue of man’s justification before God in John Calvin’s Christianae religionis institutio and in the main works of selected Polish Calvinists. This issue is related to the doctrine of predestination, i.e. the eternal predestination of man by God to salvation or damnation. Justification in Calvinist doctrine is related to Christology and soteriology. It therefore takes place before Jesus Christ, or more precisely, with the mercy flowing from his Cross. According to Calvin, there is also a close connection between justification and sanctification of man. It was noted that the problem of justification was the axis
of considerations at the Council of Trent, whose judgments in this matter were used by Calvin. The works of outstanding Calvinists, such as Mikołaj Rej, Grzegorz from Żarnowiec or Jakub Niemojewski, expanded the analysis of the doctrine of justification and predestination.