A zealous pastor, Fr. Seraphim rarely took a vacation and when he did, he was not idle but worked towards educating youth as the spiritual father of Camp NORR. As the parish grew, he and Matuska Elena developed a parochial school to educate the children and youth as Orthodox Christians and Russian Americans. Probably the most significant of his endeavors, however, was the writing of his catechetical work Zakon Bozhij (Закон Божий = The Law of God). Working late at night, he described the faith of the Orthodox Church with simple and profoundly lucid explanations. Published in 1966, this was, and remains, an influential catechetical text for Russians both abroad and in the Soviet Union where numerous copies were smuggled and copied by hand. Intended originally for youth and children, it became a respected work among adults as well, and was finally translated into English in 1992. According to Patriarch [[Alexei II (Ridiger) of Moscow|Alexei II of Moscow]], “the legacy created in the Diaspora was republished in Russia in enormous editions—Protopriest Seraphim Slobodskoy's "Law of God" alone, for instance, is used by hundreds of thousands, if not millions, of children in Sunday schools, while teenagers use this book to prepare for [[seminary]].” Many believe that it is one of the finest simple overviews of the Orthodox faith written in modern times.
For his work in producing this book, Fr. Serafim was awarded a gold pectoral cross. Elevated to the rank of [[protopriest]], he also received the kamilavka for his pastoral work
, a palitsa for 20 years service as a priest.
Constant exertion in the service of his parishioners undercut the strength of Fr. Serafim, and in 1971, at the age of 59, he reposed.