Background
Born in Vitebsk province, in the hereditary estate of Zhirovitsy, at the end of the XVI century and the beginning of the XVII century. Came from a Belarusian noble family, whose members are partly shifted to Catholicism. His parents were Orthodox.
After graduating from the course of studies at the Kyiv Bratsk Epiphany School among the best students, Kossov entered the number of monks of the Kiev-Pechersk Lavra, where the saint Petro Mohyla, with the consent of the Metropolitan Job Boretsky, sent abroad, along with other selected young people from secular and religious to receive higher education and to prepare for teaching in high school, which has been decided to set up in Kiev in the near future.
The enemy is the Union of Brest in 1596, sought the equal rights of the Orthodox clergy and katilicheskogo. Opposed the closure in 1634 the Orthodox schools. Together with the Ukrainian clergy condemned the presentation of Bogdan Khmelnitsky against Poland