Bhagavad Gita:~ Cut all such conflicting dualities (doubts) by the sword (weapon) of knowledge.+

No duality, no differentiation. Only Atman exists. Let us see in the words of Krishna:

Bhagavad Gita: 4: 22: ~ ".....who has gone beyond the conflicting dualities like good (happiness) and bad (sorrow)....."

Bhagavad Gita: 4: 42:~ ".....cut all such conflicting dualities (doubts) by the sword (weapon) of knowledge. ....."

Bhagavad Gita: 5: 18:~ “The learned men (who have come out of delusions (Māyā), got rid of Avidya) see no differentiation have an equal vision for a revered Brahmin, a cow, an elephant, a dog and a cāndāla (outcaste, rogue, mleccha, demonic person, etc)"

Bhagavad Gita: 5: 19:~ "Those who have achieved the true knowledge i.e. the 'Self-Knowledge' or the 'knowledge of Atman' and see no difference, are free from conflicting dualities have merged in Brahman"

Bhagavad Gita: 5: 20:~ "One who does not get excited out of happiness on getting good and does not get depressed on getting bad is situated in Brahman i.e. is merged in Brahman"

Bhagavad Gita: 6: 9:~ "The one who has an equal vision for a Selfless do-gooder, a friend, a foe, an unbiased, a well-wisher, a depressed and jealous man, relatives, a righteous and a sinner is the best (as he sees no duality and differentiation but sees everything as Atman)"

Bhagavad Gita: 6: 32:~ “.....as one seeks and treats oneself with equal vision, the same way one who has the equal vision for good and evil, for everybody, is the best of all."

Bhagavad Gita: 6: 8: ~ "For whom soil, a pebble, and gold are alike, he is merged in Brahman"

Bhagavad Gita: 7: 27:~ ".....people are getting entangled in the primordial ignorance (Avidya) of the conflicting dualities like good and evil, happiness and sorrow caused due to attachments, desires, and hatred....."

Bhagavad Gita: 6: 28:~ “.....who have cut off conflicting dualities (like good and evil) are determinedly in my service. ...."

Bhagavad Gita: 7: 19:~ "Such a man who has attained true knowledge, the knowledge of Self, the knowledge of Atman, worships the 'Self as~ Atman alone exists~ everything is Atman, there exists nothing except Atman. Such a man is extremely rare": ~ Santthosh Kumaar