On [[August 16]], 1892, Dn. Sebastian was ordained a [[priest]] by [[Bishop]] [[Nicholas (Ziorov) of Warsaw|Nicholas]]. He was soon sent to Minneapolis, Minnesota to replace Fr. [[Alexis of Wilkes-Barre|Alexis Toth]] as the priest of [[St. Mary Cathedral (Minneapolis, Minnesota)|St. Mary's Church]] there. While there he also taught at the Missionary School. After a year, Fr. Sebastian returned to San Francisco where he organized [[St. Sava Church (Jackson, California)|the first Serbian Orthodox Church, dedicated to St. Sava]], in Jackson, California. Additionally, Fr. Sebastian was also asked by Bishop [[Tikhon of Moscow|Tikhon]] to be a member of the [[Orthodox Church in America|North American Mission]] administration. Additionally, he was a legitimate force in helping organize the Orthodox Christians - particularly in the Pacific Northwest of the United States, though his missionary work brought him as far south as Arizona - into communities that were capable of supporting churches. Some of the places where he did this include Seattle into a parish (the future [[St. Spiridon Cathedral (Seattle, Washington)|St. Spiridon Cathedral]]), visiting the city, organizing the community, and where he even serving served as a temporary priest before Fr. [[Ambrose Vretta]]'s arrival in November of 1895, Wilkenson, Washington, Portland, Oregon, and Butte, Montana (the future [[Holy Trinity Church (Butte, Montana)|Holy Trinity Church]]). In 1902, he continued his missionary activities, returning to Alaska as [[dean]] of the Sitka deanery. While he was in Alaska, he helped establish [[St. Sava Church (Douglas, Alaska)|St. Sava Church in Douglas]].