Seraphim Papacostas studied theology at the University of Athens, thereafter serving as a high school teacher for two years, and later as a preacher at the Cathedral of Athens.
He passed the last twenty-five years of his life in the capacity of Superior of the Zoe Fraternity (1927-1954) which was established by his predecessor, Archimandrite Eusebius Matthopoulos.
As Superior of Zoe, he contributed to the establishment of associations and unions for parents, women, the young working class, students and educators. He founded, along with P. Tsirintanis, the Chrisian Union of Scientists in 1937. Father Seraphim was distinguished as an author.