The Slavic peoples today populate several nations: the Czech Repulic, Slovakia, Poland, Belarus, Russia, Ukrania, Bosnia, Bulgaria, Croatia, Macedonia, Montenegro, Serbia and Slovenia.
During Medieval times, the Slavic peoples were ready to convert to a "modern" religion. They were between three religions: Catholicism, Eastern Orthodoxy, and Islam. The vast majority of Slavs chose either Catholicism or Orthodoxy because if they became Muslim, they would no longer be able to consume alcohol.
Although we are grateful that they did not choose Islam, we wish they had the alternative of Biblical Christianity to choose from.
But there is a lesson to learn: many people choose a religious faith not on the basis of their perception of truth, but on the basis of what accommodates them best.