Bhagavad Gita Verse 19, Chapter 5

ihaiva tairjitaha sargo yeshaam saamye sthitam manaha |
nirdosham hi samam brahma tasmaadbrahmani te sthitaaha || 19 ||
 
Here in this world itself, they have conquered creation, those who establish their intellect in equanimity. For, the eternal essence is defect-free and harmonious; therefore, they are established in the eternal essence.
 
iha : here in this world
eva : itself
taiha : they
jitaha : have won
sargaha : creation / duality
yeshaam : those who
saamye : equanimity
sthitam : established in
manaha : intellect
nirdosham : defect-free
hi : for
samam : harmonious
brahma : eternal essence
tasmaad : therefore
brahmani : in the eternal essence
te : they
sthitaaha : are established
 
In the last shloka, Shri Krishna spoke about the wise person who sees the same eternal essence in everyone. Here, he goer deeper into this point and addresses some questions that could come up when trying to understand that shloka.
 
Consider a hardened criminal. Most of us would classify his behaviour as defective. Now, given the context of the previous shloka where the wise person perceives a criminal and a saint with the same vision. How does it actually happen? To address this point, Shri Krishna mentions in this shloka that the personality of the criminal has the defect, not the eternal essence. The eternal essence is inherently defect-free.
 
Another question that may arise is this. When and where does one attain the eternal essence? How much time will it take and how far away is it? The answer is that notions such as near/far, and slow/fast are dualities. Any such duality belongs to nature, not the the eternal essence. Therefore, one whose intellect has transcended duality immediately attains the eternal essence. Notions such as near/far, and slow/fast cease to have meaning.
 
Finally, Shri Krishna explains that attaining the eternal essence is possible here and now. We do not have to wait for another birth. Following the technique of karma yoga, we have to purify our mind and make it steady and harmonious, so that it can meditate on the eternal essence.