A way of life very dangerous to a tiny parasitic elite that wants to feed off the masses.
This wave of terror was so successful that it laid the foundation of a society without any moral and spiritual roots and community bonds, and produced people dependent on the state.
When the Thirty Years War in Europe was over and had successfully broken the backbone of it's population in 1648, it only took 5 years until the same psy-op was conducted on the Russian people.
After a volcanic eruption in Peru (supposedly) and the following climate changes, one third of the Russian people had died at the Beginning of the 17th Century in the Famine of 1601-1603. It started a process that is surprisingly similar to the official narrative of the Thirty-Years War in Europe: We are told Protestants, Catholics and Swedish, German and Polish Armies all came together in a gigantic idiotic war supplemented with civil uprisings, lootings and Tartarian Hordes depopulating the south Borders of Russia. Entire cities destroyed and depopulated. Sometimes by Protestant forces, sometimes by Catholics.
It was a time of moral decay and these times especially people with high moral values became easy targets, while ruthless people had a higher chance of survival. This shock was probably already enough to sever the spiritual roots of the people to a very high degree.
After the people had been weakened, the same operation that before had eliminated the old way of life in Central Europe was brought to Russia in 1653 with the reforms of Patriarch Nikon.
In contrast to the times of the 'Reformation', this time even the official history admits that it was an attempt to suppress an independent way of life and change religion into a centralized power structure.