Kuntsevych faced a daunting task of bringing the local populace to accept union with Rome. He faced stiff opposition from the monks, who feared liturgical Latinisation of the Byzantine Rite. As archeparch he: restored the churches: issued a catechism to the clergy, with instructions that it should be memorized; composed rules for priestly life, and entrusted deacons the task of superintending their observance; assembled synods in various towns in the dioceses; and firmly opposed the Grand Chancellor of the Grand Duchy of Lithuania, Lew Sapieha, who wished to make what Josaphat saw as too many concessions to the Eastern Orthodox. Throughout all his strivings and all his occupations, he continued his religious devotion as a monk, and never abated his desire for mortification of the flesh. Through all this he was successful in winning over a large portion of the people.