I have said before that the polytheism of the pre-Christian world did not disappear with the arrival of Christianity; it was simply transformed. The pantheon of the old gods was replaced by the “pantheon” of God the Father, Jesus, Mary, the angels and the saints. Where people once turned to this or that lesser deity for help with such things as illness and crops, they now turned to Christian saints.
In the Slavic world, two very important pre-Christian gods were Perun and Veles. Perun was a sky god associated with thunder, lightning, and fire. Veles was a lower earth god associated with herds and flocks.
Now, as one might imagine, both of these things were very important to the average person concerned about his crops and his flocks.
So what happened when Christianity was imposed on such people? They looked for replacements. Here is an icon of the Prophet Elia/Ilya (at left) and of St. Vlasiy, called “Blaise” in the West:
Christianity has the Prophet Elijah, called Ilya in the Slavic world. In the Old Testament story, Ilya was taken up to heaven in a fiery chariot. His day of celebration came late in July, a time when peasants were very concerned about the effects of weather on their crops. So the characteristics of the thunder god Perun were simply transferred to the Prophet Elijah, who was believed to roll across the heavens in his fiery wagon, making the sound of thunder, which is why in Serbia he is called Sveti Ilija Gromovnik — ” Holy Elijah the Thunderer.” Now you know why there are so many icons of Elijah. When the images of the old gods were done away with, their place was taken by icons. So polytheism did not die out with the arrival of Christianity; it just put on different clothes.
In some places, even the “blood” sacrifices to the old gods survive in the veneration of Elijah. In the Balkans, for example, there is a tradition for a family to kill the oldest rooster each year on Ilinden –Ilya’s Day; and also a ram or bull is killed and boiled so that Ilya will not withhold rain for the crops.
The old rival of Perun in the Slavic pantheon was the god Veles/Volos. When Christianity was introduced (one could say “imposed”), it was not difficult to find a counterpart for Veles in the ranks of saints, because one particular saint had a very similar-sounding name — Vlasiy (Vlasios in Greek, Vlas in Bulgarian). It did not matter that hagiography related that Vlasiy had been a bishop at Sebaste (now Sivas in Turkey) in the late 3rd-early 4th century. There was a legend that he healed wild animals, and that, combined with his name, made him the new Veles, protector of herds and flocks. That is why an icon of Vlasiy was often hung in the shed where livestock was kept. His day of commemoration was in February.