It’s There in the Name – The ‘Preliminaries’ Must Come First
Buddhism encourages us to examine our life and situation carefully so that we can see things as they are. When we see the nature of our cyclic existence, we see that it is characterised by suffering and dissatisfaction, and we begin to long for freedom and the peace of transcendence. This insight and subsequent feeling is what we call renunciation.
If you have not yet understood how cyclic existence is by its very nature suffering, there is no way you can generate the mind of awakening (bodhichitta). Then how could you generate the wish to lead sentient beings to a state beyond suffering when you see them as being pretty much fine as they are?
This is why it is imperative that the practice of the lower vehicle, and the sense of renunciation it inspires, precedes the practice of the greater vehicle. The preliminaries (ngondro) are the foundation of all progress on the path.