Long ago, the Slavs were a shy people living in the forests of what eventually became Russia.
And then, about 700 AD, the Northmen (Vikings) came. The Northmen subjugated the Slavs. They collected furs, honey and wax from the timid Slavs hiding in the forests.
The Northmen soon became Tsars. This word Tsar is also spelled Czar. It derives from Byzantium and the word “Caesar”. The German word “Kaiser” is also derived from “Caesar.”
The Tsar Northmen slowly adopted the Orthodox Christian religion of Byzantium. This Orthodox Christian religion was a split-off from Rome’s Christianity. There had been a schism between Rome and Constantinople: Rome was Latin; Constantinople was Greek.
In 1939, Winston Churchill had this to say about Russia: “I cannot forecast to you the action of Russia. It is a riddle, wrapped in a mystery, inside an enigma…” 
In 1978, Alexander Solzhenitsyn said something similar: “Every ancient and deeply rooted self-contained culture, especially if it is spread over a wide part of the earth’s surface, constitutes a self-contained world, full of riddles and surprises to Western thinking,” stated Solzhenitsyn. “For one thousand years Russia belonged to such a category, although Western thinking systematically committed the mistake of denying its special character and therefore never understood it…” 
Ever since the schism between Rome and Constantinople (now Istanbul), two separate world views have existed. The Latin Church (Rome) was more this-worldly, believing the world was basically good. So was the flesh basically good. The world and the flesh were made by God. God had become man in a human body. There would even be a resurrection of the body on the last day.
But for the Slav religion (Russian Orthodox), this world, the human body, pain, and death were of little importance. In this world, the Prince of Lies dominated and there was little one could do.
The this-worldliness of the Latin Church fostered increasing materialism. But for the Russians there was an other-worldly path. The Slavs developed a profound spirituality and what would seem to Westerners even an irrationality, more in touch with vital forces than with their outward signs. Fyodor Dostoevsky, the Russian 19th-century author, wanted “to free humanity from the tyranny of two plus two equals four.” 
For the Russian soul, any physical defeat equals a spiritual victory. To Dostoevsky, every object and act is only a symbol for hidden spiritual truths. In his stories, Dostoevsky’s characters appear incomprehensible to the Western mind: if a character obtains a fortune he exclaims, “I am ruined!”; if he is acquitted of a murder charge, he cries, “I am condemned!” 
Recently, syndicated columnist Patrick J. Buchanan asked, “Is God now on Russia’s side?” Buchanan reported that “ex-Communist Whittaker Chambers who exposed Alger Hiss as a Soviet spy, was, at the time of his death in 1964, writing a book on ‘The Third Rome.'” The first Rome was of course Rome itself. The second Rome was Constantinople, Byzantium, (today’s Istanbul). “The successor city to Byzantium, the Third Rome, the last Rome to the old believers, was – Moscow.” (Further background: Scourges On The Back of Jesus, Ersjdamoo’s Blog entry of April 13, 2014.)
For Dostoevsky, there was a huge difference between outward appearance and inner significance. This amounts to a contradiction between God (inner significance) and the Devil (outward appearance). The struggle between the two happens in our souls, and it is ongoing. This struggle is the cause of suffering. The only solution is to face the suffering resolutely. Such suffering purges us from all artificiality. For Dostoevsky, the Russian people, because of their greater suffering and their greater spirituality, are the hope of the world. 
From this begins Pan-Slavism. The spiritually superior Russian people, by virtue of their suffering which has made them the brothers and sisters of all other suffering people, must save the world from the forces of evil by taking up the sword of righteousness. “Constantinople will be seized, all the Slavs will be liberated, and Europe and the world will be forced into freedom by conquest, so that Moscow may become the Third Rome.” 
——- Sources ——-
 “The meaning and origin of the expression: A riddle wrapped up in an enigma”, http://www.phrases.org.uk/meanings/31000.html
 “A World Split Apart — Commencement Address Delivered At Harvard University, June 8, 1978”, by Alexander I. Solzhenitsyn. http://www.orthodoxytoday.org/articles/SolzhenitsynHarvard.php
 Dostoevsky qtd. in Tragedy and Hope, by Carroll Quigley. New York: Macmillan, 1966
 Tragedy and Hope, by Carroll Quigley. New York: Macmillan, 1966