St. Ambrose treating Easter in the letter to “The bisftops establisfted througftout tfte province of Aemilia”

The article presents the letter of St Ambrose to «the lords, his brethren most beloved, the bishops established throughout the province of Aemilia», and highlights the main features and its central theme: the establishment by God of Easter and its day. We explored that St. Ambrose’s theological approach to understanding Easter is based on the unity of the Old and New Testaments and interpretation of the Old Testament establishment in the spirit of the New Testament. The analysis of St. Ambrose’s position reveals that Easter must be determined according to Bible’s standards and be celebrated on Sunday after the 14th Lune of the «month of the new (corns)». We consider theologically justified conclusion by St Ambrose about expediency to transfer Easter to the next Sunday (in the case of the coincidence between the 14th day of the Easter lunar month and Sunday), as, first, a basis of the necessity to celebrate Easter exactly on Sunday and, second, as reason of highlighting the Easter Sunday among other Sundays in the year. In this regard the paper analyses the interpretation by St Ambrose of Easter Gospel Reading about the Law given through Moses and about the grace and truth that came through Jesus Christ (Jn 1:17).