Over centuries, Mari people has gone through the Christianization, forcefully imposed on them, through the era of Soviet atheism and faced many other challenges, when all forms of prayers and sacrifices were prohibited by the state, but somehow managed to preserve their faith and culture. Nature is the core idea of their worldview and culture. Mari people worship the world that surrounds them. It is believed that karts (pagan priests) send their prayers to the Gods of Earth and the Gods of Sky through the sacred trees, that perform the function of an altar. A sacred grove plays the role of a temple, the shrine that has been built by Mother Nature, filled with Her vital powers as a child, whom She nursed. Mother Nature is God, Savior and the Eternity, that makes a man’s life meaningful. Mari people believe that Nature is the house that they are to pass on to their children and grand children, so it must be respected and treated properly. They oppose ideas of modern consumerism and hectic urban life where money is the chief aim. While most of young men flee the countryside in order to make money in the capital, Mari people stay and preserve their traditions. Their ideas of progress and success differ from usual understanding. Being successful to Mari people is leading an honest life, free from lies, hypocrisy and greed, life that is filled with deep respect to the world that surrounds them, and belief that this world, every inch of it, is filled with life, that the Nature had breathed in.