The Greek esothen (Strong's G2081) means 'within,' 'inwardly,' or 'from inside.' It is the adverb form of eso (inner/inside). In the New Testament it is used to describe the inner life of persons — particularly in Jesus's critiques of the Pharisees and in Paul's teaching on the inner transformation of the heart. The word consistently points to the interior reality that either validates or exposes the exterior presentation.
Jesus's use of esothen in His Pharisee critiques is among His sharpest theological challenges. 'You clean the outside of the cup and the dish, but inside (esothen) they are full of greed and self-indulgence' (Matthew 23:25). 'Inwardly (esothen) they are ravening wolves' (Matthew 7:15). 'Inwardly (esothen) you are full of dead men's bones' (Matthew 23:27). The consistent theme: God reads the inside, not the outside. Religion that performs for human observers while harboring corruption within is an abomination. The gospel's work is interior transformation — the new creation is from the inside out, beginning in the hidden depths of the heart.