Nikon was born in Pontus (modern northeastern Turkey) or in Argos, of Armenian or Greek origin.

When he was young, Nikon had gone to a monastery known as Khrysopetro ("Golden Stone") located on the borders of Pontus and Paphlagonia, where he spent twelve years, living an ascetic life of prayer and penance, so extreme that his brothers had tried to persuade him to lessen his regimen.

His abbot, impressed by his spiritual conferences and worried that his newly returned father would draw him from the ascetic life, had sent him out into the world to preach.

After his departure, he traveled to Asia Minor and preached repentance there for three years before moving on.

Following the expulsion of the Arabs from Crete in 961 by Nikephoros Phokas, he had become active as a missionary preacher on the island, struggling to return recent converts of Islam back to Christianity.

The area had been a Muslim emirate since the 820s, and in that time Christianity in the area had weakened, many former Christians having converted to Islam.

Even those who had remained faithful to Christianity had somewhat lost contact with the living tradition, churches and monasteries having fallen into decay.

The people in the region were, as quoted from Nikon's biography, not Islamic, but rather Christians who had been corrupted "by time and long fellowship with the Saracens."

Nikon was forced to change his tactics on Crete, now having to use his wit to lead his listeners to repentance, rather than just preaching the message of repentance.

It was there that he acquired the nickname metanoite (Greek for "penitent/repent") for his habit of using it as a preface to all his sermons.

After spending five years on Crete, Nikon had gone on to Epidauros, Athens, and Euboea.

He had then traveled to Thebes and Corinth, and finally down into the Peloponnese, particularly to Sparta, where he constructs three churches and a monastery and continues his preaching and teachings, which are reportedly confirmed by miracles.

The Peloponnese is represented as a land full of demons, of which Nikon is constantly struggling against.

Upon being approached in 985 to try to stop a plague of pestilence, Nikon refuses until the Jews are expelled so he “would not be contaminated by their customs...or religion.”