While he supported the incorporation of left-bank Ukraine into the Tsardom of Russia, he also defended the independence of the Kyiv metropolis to the Patriarch of Moscow.

In 1658, when the presence of Muscovite troops forced Metropolitan Balaban to move his episcopal seat to Chyhyryn, the government in Moscow appointed Baranovych in his place.

In 1667, at a local Council in Moscow, a decision was made to elevate the Chernihiv diocese to an archdiocese with Lazar Baranovych as archbishop.

Baranovych may have assumed the title of "Metropolitan of Kyiv, Galicia and all Ruthenia" or locum tenens in pretence.

The publications of his sermons, written in a baroque style in Church Slavonic language, include: He is the author of several polemical works against Catholicism in Polish and Church Slavonic (see also Polemical literature); of a poetry collection in Polish, Lutnia Apollinowa (Apollo's Lute, 1671); and of a large correspondence.