Plymouth Brethren
Danielsen quit the established Faroese People's Church in 1916 and attached himself to the Brøðrasamkoman (Faroese Plymouth Brethren). He married in 1920 and moved with his wife to Fuglafjørður, where he worked as a full-time worker in Siloa Assembly and itinerary missionary for the Faroese Plymouth Brethren.