[2] Sunarko was educated at St. Peter Canisius Middle Seminary, in the town of Mertoyudan in Magelang Regency from 1982 to 1987.

After completing his studies at the Mertoyudan Seminary, he was accepted as a candidate member of the Franciscans and underwent training as a novitiate.

[3] After his ordination Sunarko was the provincial head of the Franciscan friars in Indonesia, and served as a priest in the Diocese of Jayapura.

[3] On 28 June 2017 it was announced that Sunarko had been nominated as the bishop of Pangkalpinang, succeeding Hilarius Moa Nurak who had died in April of the previous year.

On 23 September of that year, Sunarko was ordained bishop of the diocese of Pangkalpinang by archbishop of Palembang, Aloysius Sudarso.