Bhagavad Gita has discussed in detail various evils which cause the human suffering. It has also been analysed as to why do these afflictions arise and how can they be managed.

Shri Krishna has identified lust, anger and greed as the main culprits which lead to one’s downfall. Hence, in shloka 16.21, he has termed them as three entry gates of hell. Further, he has cautioned that they lead to degradation of the soul and, therefore, should be abandoned.
in the next shloka i.e. in shloka 16.22, it is stated that one who is freed from these three gates of darkness, he does what is good for himself ; and thus attains to the supreme destination. In other words, Krishna tells man that the more a person is liberated from these three vices, the more he becomes pure and ultimately reaches the highest position of self-realisation i.e. of oneness with Ishvara.
Mischiefs of lust have further been elaborated in shlokas 3.36 to 3.39. When asked by Arjuna as to what impels man to commit sin, as if by force, even against his own will ; Shri Krishna replied that sin is committed due to lust. The lust is born of the mode of passion (rajas guna) and it later emerges as anger.

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