[2] Goldstein was born in Shumen, a city in the eastern part of the Principality of Bulgaria, to a Jewish family.
In 1915 he left France for Zurich, Switzerland, where he met and befriended Vladimir Lenin, the future leader of the October Revolution of 1917.
He supported the efforts of some extreme-left factions to force the Bulgarian party to action through acts of terrorism, such as the assassination of the former Interior Minister Mihail Takev in January 1920.
Goldstein was active by signing a paper in Vienna (the so-called May Manifesto), in which the objectives of the unified Macedonian liberation movement were presented.
After the death of Lenin in 1924, Goldstein sided with the left opposition of the Communist Party of the Soviet Union, possibly due to Adolph Joffe's influence.