In short, the country was polluted with "heresy"-- a subtle, evil influence lurking in everything foreign, and very dangerous to the spiritual and temporal welfare of the Faithful--something of the nature of an epidemic, but infinitely more dangerous; for disease kills merely the body, whereas "heresy" kills the soul, and causes both soul and body to be cast into hell-fire.
Had the Government introduced the innovations slowly and cautiously, respecting as far as possible all outward forms, it might have effected much without producing a religious panic; but, instead of acting circumspectly as the occasion demanded, it ran full-tilt against the ancient prejudices and superstitious fears, and drove the people into open resistance.

When the art of printing was introduced, it became necessary to choose the best texts of the Liturgy, Psalter, and other religious books, and on examination it was found that, through the ignorance and carelessness of copyists, numerous errors had crept into the manuscripts in use.

This discovery led to further investigation, which showed that certain irregularities had likewise crept into the ceremonial.

The chief of the clerical errors lay in the orthography of the word "Jesus," and the chief irregularity in the ceremonial regarded the position of the fingers when making the sign of the cross.
To correct these errors the celebrated Nikon, who was Patriarch in the time of Tsar Alexis, father of Peter the Great, ordered all the old liturgical books and the old Icons to be called in, and new ones to be distributed; but the clergy and the people resisted.

Believing these "Nikonian novelties" to be heretical, they clung to their old Icons, their old missals and their old religious customs as the sole anchors of safety which could save the Faithful from drifting to perdition.