Sadhana simply makes you strong, mentally, physically, to be able to let go. That's all sadhana does. Sadhana never enlightens you. It makes you one-pointed, in your quest for realization. It makes you compassionate. It develops humility, power. It transcends all fear. And when you finally get to that point, the inner Guru grabs a hold of your mind, yanks it into the Heart, and you become liberated.