Karma and Its effect
The main teachings of the Buddha constitute the law of cause and effect. Although all the beings in samsara seek joy and shun suffering they are ignorant of the cause of happiness or sorrow. In fact, the happiness and suffering of the sentient beings are the results of their own virtuous or non-virtuous action.
Guru Suvarnadvipa of Indonesia once told atisha Dipamkara, “Until you attain freedom from the delusion of ego-grasping, follow the law of cause and effect.”
With the purpose of creating fear in the minds of people from indulging in non-virtuous acts and understanding the essence of defilements, various wrathful images are being manifested by the enlightened beings specially in Vajrayana tradition.