According to Osho, a guru undoes and redoes you: he destroys the false self (ego, conditioning, mind) and gives you new life, a cross and a resurrection. Outsiders only see the undoing; the resurrection is known only by participating as a disciple, falling en rapport. The Master's ultimate work is to transform the disciple into a Master in his own right.
A true guru trims away your old habits so a new you can grow, but you must join in and trust to feel it.