Elder Nektarios was born Kyriakos Marmarinos in Aegina on November 3, 1921. He is spiritual child of St. Hieronymus of Aegina. He graduated from the seminary in Corinth and was ordained a deacon by Bishop Michael of Corinth in the Church of Virgin Mary in the neighborhood Synoikismos (meaning settlement) of Corinth. On November 8, 1945, he was raised to the dignity of archimandrite in the Church of St. Paul in Corinth.
In 1952, he founded the Monastery of St. Patapios in Loutraki, Greece. In 1977, he founded the Monastery of St. Paul in Mount Gerania (it has now been abandoned) and the male monastery of St. Nickolaos at the place New Malagari of Perachora (a village close to Loutraki). Recently he founded the male monastery of the three hierarchs in Perachora.
He served as a chancellor of the Diocese of Corinth. In 2006, he was honored by the City of Corinth with the golden key of the city and also honored by the then Archbishop of Athens and All Greece Metr. Christodoulos with the gold medal for his missionary work. Since 1940, Elder Nektarios has taught Sunday school every Sunday afternoon at the Cultural Center of the Church of Virgin Mary at Synoikismos, in Corinth.
At an advanced age, he still teaches in Sunday school at Synoikismos and travels among the villages and towns of the province of Corinthia teaching the Word of the Gospel. Also, every Friday morning he visits the Monastery of St. Patapios in Loutraki, directing the souls of the nuns toward Salvation. Often on Sundays he preaches at the male monastery of the Three Hierarchs in Perachora. His missionary effort is well known and according to nun Patapia he has contributed greatly to the Monastery of St. Patapios that he founded.
- "Precepts and teachings of Elder Nektarios Marmarinos" [Edition of the Holy Monastery of Saint Patapios, Loutraki, 2010]
- "Geraneios Aura. Consulting speeches of Elder Nektarios Marmarinos ", [Edition of the Holy Monastery of Saint Patapios, Loutraki, 2007]
- "Saint Patapios" [Stylianos Papadopoulos, professor of the University of Athens, Holy Monastery of Saint Patapios, Loutraki, Greece, edition 2006).
- "St. Patapios and his miracles," [Dr. Charalambos Busias, edition of Holy Monastery of Saint Patapios Loutraki 2004]