That which is not present in deep dreamless sleep is not real

Peace can reign only where there is no disturbance, and disturbance is due to thoughts that arise in the mind.

The world is not outside you.

Calmness is the criterion of spiritual progress. Plunge the purified mind into the Heart. Then the work is over.

Meditation helps concentration of the mind. Then the mind is free from thoughts and is in the meditated form.

Concentration is not thinking of one thing. On the contrary, it is excluding all thoughts, since all thoughts obstruct the sense of one's true being. All efforts are to be directed simply to removing the veil of ignorance. Concentrating the mind solely on the Self will lead to happiness or bliss. Drawing in the thoughts, restraining them and preventing them from straying outwards is called detachment (vairagya). Fixing them in the Self is spiritual practice (sadhana). Concentrating on the heart is the same as concentrating on the Self. Heart is another name for Self.

Realisation is our nature. It is nothing new to be gained. What is new cannot be eternal. Therefore there is no need for doubting if one would lose or gain the Self.