As long as you have negative thoughts in your mind, no matter how much you attempt to be pure, you cannot become pure. It is said that everything that appears and exists is all-encompassing purity, and also that within every sentient being dwells the buddha. The Secret Mantra Vajrayana teaches that the external universe is an immeasurable palace, and all the internal sentient beings are dakas and dakinis. This is how it truly is in reality. When you understand this, your mind becomes like space, very blissful and happy.

-- Garchen Rinpoche