Robert Matthews was born in Cambridge, New York, in 1788, into a family that followed strict Scottish Calvinist beliefs that rejected "burghers" and emphasized class equality and patriarchy. Matthews married his wife Margaret, and they had six children. Three of their sons die in childhood. After leaving Manhattan, Matthews opened a store in Coila, a Scottish neighborhood in Cambridge, but soon went bankrupt due to a lack of business acumen. This financial failure, combined with the death of his sons and his own bout with illness, negatively affected his mental health.

Matthews started to believe that he was receiving prophetic visions from God. He convinced himself and others that he was God's prophetic agent on Earth, charged with the duty to prepare the world for God’s second coming. He took the name Prophet Matthias, Prophet of the God of the Jews, and claimed to be the incarnation of the age-old “Spirit of Truth.” Matthews began preaching throughout New York. He claimed to be in direct communication with God, and his promises of prosperity and freedom resonated with the needy, the poor, and the gullible. He manipulated his followers’ innate religious inclinations and their perennial search for spiritual fulfillment. Matthews had great charisma and the ability to charm and win over followers by beguiling and seducing them into doing what he wanted.