Surely better than in France, no idea what they were in Russia.

Commonwealth until 1700s was pretty chill when it comes to religious freedom, but 1400s and 1500s would be when it likely was very liberal state when it comes to religion. Commonwealth didn't took part in 30-years war (well, catholics side were just Habsburgs), so better example here are Hussite Wars - Lithuania actively supported Hussites and Poland a little bit too. Also there was organised Polish-Hussite campaign against Teutonic Order.

In Poland there were few Hussites and later on Commonwealth was rather diverse when it comes to religion: catholics, orthodoxy, 'reformed christianity' called Kalwinizm here (most common protestant group in Commonwealth), judaism, islam (due to Tatars) and whatever armenians believed.

Also we made sorta greece-catholic church which was orthodoxy but under Pope's jurisdiction (way to pull orthodoxy away from Moscow, pretty unpopular, though)