"Salvation" derives from the Latin word "salva", meaning saved.
When discussing salvation, it arises that we need to figure out exactly what it is that we are being saved from. "Sin" – the deeds of misguided intent or will. It is presumed that as inhabitants of the material world, sin is all around us, and a persistent burden. Throughout Isaiah is a recurring motif; the people of Israel persist in their iniquities, "and yet the Lord's hand is still upraised." Why, then, does it remain upraised?
It's a bit like "there's all of these chaotic and inexplicable things happening around us" and salvation is the thing that puts a window on it, and affords some context and perspective. Salvation is at the crux between the symbolic, material world and the ideal, imaginary world; it is representative of the real, in Lacanian terms.
The world of distinctions exists so that some finitude may be made manifest; the knowledge of good and evil, the contraction of infinity to afford a time and place of here and now, and the divine freedom imbued in everything so that anything may exist at all.
The term nirvana in Buddhism, meaning "extinguishing", is closely related to salvation. Nirvana is reached when the fires of greed, hatred, and ignorance are extinguished, the will of the flesh overcome and supplanted by enlightenment. Repentance is a necessary prerequisite for salvation, because it is the thing that prompts contextualization. The state that great mystics and yogis strive to attain is kenosis and śūnyatā, self-hollowing. Suddenly, space is made in this vessel of consciousness so that redemption may occur.
As if we are here so that we may not be here; as if the world exists so that we can choose to turn towards God; as if we are hungry so that we may be full, and we become full so that we may become hungry; salvation is the transcendence of the world of distinctions from within the world itself. Redemption is the contact with this limitless source of light, this aether, without from within.