For Vivekanand, the human being had ultimate power to do anything and everything. For him, this was a simple derivative of Vedant, which saw man as God. He asked all his countrymen to believe in this and act.
It is surprising since then the amount of evidence that has piled up in how self-efficacy is a key factor the most unfortunate to get out of their plight, but also one of the key characteristics of the top achievers in the world. For psychologists, self-efficacy is a belief. For Vivekananda, a realization of the ultimate truth.