It wasn't easy being a rebel in the Soviet Union, back in the 1970s when Sergy Ribko was a rock drummer who cherished whatever scraps of music and media made it through the Iron Curtain. Most of all, the self-proclaimed hippy who would later become a Russian Orthodox priest loved The Beatles.

The band taught "us to think about the meaning of life, good and evil, even about God and eternity, taught us to understand and love freedom in all its manifestations," wrote Ribko, in an open letter addressed to the "Dear and Highly Esteemed Sir Paul McCartney" that has been translated from Russian and circulated on the Internet.

"The absence of freedom was extremely felt in that totalitarian country, in which we were doomed to be born and live. The 'iron curtain' separated us ... from our mates in the free world where they could create and live according to their desires. ... Moreover it tried to hide from us the Heavens and God."

What would inspire the rector of Moscow's Church of the Holy Spirit to write such a personal letter to a rock patriarch in the West?

Here's the blunt answer -- Pussy Riot.

McCartney released a letter backing the members of this infamous music group who were recently sentenced to two years in prison for "hooliganism motivated by religious hatred." Their crime was a "punk prayer" in which they pleaded, in highly profane terms, with the Virgin Mary to oust President Vladimir Putin.

"I hope you can stay strong," concluded McCartney, "and believe that I and many others like me who believe in free speech will do everything in our power to support you and the idea of artistic freedom."

For Father Ribko and many others, the key is not that Pussy Riot attacked Putin, but that the group's members recorded their YouTube video as they danced, prostrated and pretended to pray directly in front of the holy doors at the altar of the Cathedral of Christ the Savior. The video included images from another church invasion, as well.

"Some months ago Russia witnessed an act of evil. We, Russian believers, perceive this event in this way," wrote the monk.

"All this Bacchanalia was filmed and shown to the world. ... When Pussy Riot blaspheme in the street, it is their private affair. Many people do the same. But if they break into our church, disturbing praying people, blaming our God, out faith, our patriarch, they offend personally each of us."

It's crucial that these events have unfolded in a land still struggling after a blood-soaked century that included the worst sustained persecution in Christian history. The Communists closed 98 percent of Russia's churches and killed 200,000 bishops, priests, monks and nuns, while another 500,000 or more believers were sent to die in labor camps. Millions more died in purges under Joseph Stalin.

Members of the Soviet League of the Militant Godless -- including Alexandra Kollontai, a self-proclaimed "female Antichrist" -- took special glee in vandalizing churches, desecrating the relics of saints and performing profane, crude, blasphemous skits in, or even on, the altars of Orthodox sanctuaries. As their ultimate act of desecration, the Soviets in 1931 leveled the Cathedral of Christ the Savior.

"Christ the Savior was a central shrine both of the Orthodox faith and of Russian national pride, and for that reason, the Bolsheviks targeted it for destruction," noted historian Philip Jenkins, author of "The Lost History of Christianity" and numerous other works, in an online commentary about the Pussy Riot case.

"Not until 1990 did a new regime permit a rebuilding, funded largely by ordinary believers, and the vast new structure was consecrated in 2000. The cathedral is thus a primary memorial to the restoration of Russia's Christianity after a savage persecution."

For many believers, these new acts of sacrilege at the altar of this symbolic cathedral resembled old Russian nightmares. Try to imagine, wrote Jenkins, protesters seizing a European synagogue that had been rebuilt after the Holocaust and using it as the setting for a profane video mocking Jewish prayers.

"Not only would international media fully support the governments in those circumstances, but they would complain bitterly if police and courts showed any signs of leniency," argued Jenkins. "However serious a group's grievances, there is absolutely no justification for expressing them with such mind-boggling historical insensitivity, and in such a place. Anywhere but there!"