Duality is one of the basic concepts in the Hinduism. When the Lord created the universes, he also created the three basic qualities or the gunas, namely satva, rajas and tamas. 

The dualities are born out of the gunas and manifest as the pair of opposites, good and bad – light and darkness – death and immortality etc. In order to attain the moksha or the eternal salvation, one has not only to overcome the negative qualities of rajas and tamas and attains the virtuous state by cultivating the satvic qualities, but ultimately transcend the dualities of opposites to attain moksha.The Lord in the Bhagavad-Gita   makes this point clear in describing the qualities of Karma yogi (Gita Ch.4 –22).

By moksha or salvation is meant the breaking of the perpetual cycle of birth and death. Even noble birth, noble qualities and great achievements could only ultimately lead to misery. Adi Sankara proclaims this eternal truth in his “Bhaja Govindam” (verse 21) and appeals to the Lord for mercy. Western ideas on the subject are somewhat similar when Tomas Gray states “the path of glory lead but to the grave”.

The existence of dualities is a fact of our very existence. We shall strive to overcome first the negative qualities of tamas and rajas and then attempt to overcome the deeds, which will lead to eternal bliss. The first step in that direction, as our saints have pointed out, is to pray to the Lord “Asato ma sat gamaya, tamaso ma jyotir gamaya, mritoyor ma amrtham gamaya, om shanti, shanti, shanti " (Lead me from evil to God, light to darkness and from death to immortality – let there be peace, peace and peace).