The life of St Nicetas of Novgorod
Alone there, he fell into a spiritual deception that the desert tradition had long warned against: a demon appeared to him disguised as an angel of light, and Niketas, deceived, bowed down and accepted its guidance, which told him that prayer itself was no longer necessary for one so advanced, that study alone would suffice while the demon prayed in his place. Under this influence he grew remarkably learned in the books of the Old Testament, able to recite them at length, yet he would neither read from the Gospels himself nor bear to hear them read by others, a telling gap the monastery's elders eventually recognized as proof of what had actually happened to him. They came to his cell, prayed over him, and drove the deceiving spirit out, and Niketas, understanding at last how far he had fallen, wept bitterly and gave himself over afterward to a genuine, hard-won humility and obedience that in time restored what his own presumption had nearly destroyed. In 1096 he was raised to the episcopal throne of Novgorod, where he served for thirteen years and was remembered for miracles worked through his prayers, a very different man from the overconfident young hermit he had once been. He reposed in that city in 1109, and when his relics were later found incorrupt, the Church counted him among its saints.

