The three obstacles are:
- the obstacle of earthly desires;
- the obstacle of karma (the negative actions or offenses we commit in this life); and
- the obstacle of retribution (the negative effects of our actions in past lives, or karma).
The four devils are:
- the hindrance of the five components—hindrances caused by one’s own physical and mental functions;
- the hindrance of earthly desires—hindrances arising from greed, anger and foolishness;
- the hindrance of death—one’s own untimely death obstructing one’s Buddhist practice or doubts arising from the untimely death of a fellow practitioner; and
- the hindrance of the devil king of the sixth heaven—a strong negative influence taking various forms to cause practitioners to discard their Buddhist practice.
The three obstacles and four devils are functions that sap the bright, positive life condition we gain from our practice; they weaken our spirit to fight for our own happiness and that of others, leaving us with diminished courage and wisdom. In particular, the devil king of the sixth heaven is described as being most powerful. It represents negative functions that can operate through influential people in our environment to discourage us from pursuing our Buddhist practice and keep us in a place of victimhood and suffering. The function arises from the human tendency to be ignorant of the fundamental dignity of life and to deny the noble potential for Buddhahood that all people possess. That tendency or ignorance is known as fundamental darkness. But more important than wondering what category of obstacle or devil our problems fall into is to recognize those things that hinder our Buddhist practice and challenge them with faith, prayer and action. Lasting happiness can be achieved through learning to win over our inner darkness, or ignorance.