Bhagavad Geeta Chapter 9 - The Royal Secret

Verses 2,3

chapter 9 verse 2  chapter 9 verse 3

2. Royal Science, royal secret, the supreme purifier is this, realisable by direct intuitional knowledge, according to the dharma, very easy to perform, imperishable.

3. Persons without faith in this dharma (the divine self), O Parantapa! Without attaining Me, return to the path of rebirth, fraught with death.