People can spend their entire life searching for enlightenment outside, travelling the whole world from the bottom of the oceans to the top of the mountains - they can search as much as they like, but it won't be found anywhere other than inside that which is doing the searching.
Until grasping mind ceases in stainless space, the karma of cause and result manifest compounded by the mind, and performed by the mind. All these phenomena occur in mind. The mind names the appearances of the mind, so therefore, in order to subdue the mind of delusion, be diligent.
So much of our distress and suffering comes from the unrealistic expectations and negative reactions produced by our own mind. Our desire creates possessiveness and grasping as we fasten on to certain objects, people, or experiences for gratification. When objects satisfy us we become attached to them. The stronger our attachment, the tighter our grip and the more anxious we feel about defending our territory and possessions. Whatever we care about is idealised and must be kept safe. If our craving for something is frustrated or disappointed, we respond with aversion. When an object does not satisfy us, we angrily reject it. Deciding that it was the wrong thing all along, we set off again in pursuit of a different objective: something else, something better, something new.
Ringu Tulku Rinpoche
By detaching itself from the duality of observation and observer, the mind achieves self-liberation from division; by thus smashing the contrived practitioner, the mind frees itself from striving and seeking; by discarding the concern for the fruit of inner development, the meditator unshackles himself from hope and fear; by eliminating the sense of the “self” or the “I”, the mind emerges victorious in its battle against inner adversaries; by dismantling the clinging to substance, the meditator will gain liberation from both samsara and nirvana.
Since [true reality] is without discursiveness, it is peace. Since it is peace, it is the sphere of non-conceptual wisdom. Since it is the sphere of nonconceptual wisdom, it cannot be known through something else. Since words do not apply to that which cannot be known through something other [than this wisdom], the very nature of true reality is perfectly beyond the superimpositions of words.