Bhagavad Gita Verse 27, Chapter 13

samam sarveshu bhooteshu tishthantam parameshvaram |
vinashyatsvavinashyantam yaha pashyati sa pashyati || 27 ||
 
He who sees the supreme lord established equally in all beings, as the imperishable within the perishable, he sees (correctly).
 
samam : equally
sarveshu : all
bhooteshu : beings
tishthantam : established
parameshvaram : supreme lord
vinashyatsu : perishable
avinashyantam : imperishable
yaha : who
pashyati : sees
saha : he
pashyati : sees
 
When a nation is fighting for its independence from an invader, freedom fighters always urge the citizens to emphasize that which is common among them and de-emphasize that which is different. In India, freedom fighters had to urge its citizens to overcome their differences of region and religion, and emphasize the idea of a united Indian nation. Unless the citizens stopped identifying themselves with a certain region/religion and started identifying themselves as Indians, there was no chance of India gaining independence.
 
Similarly, all of us tend to focus on each others physical appearances, words, ideas, thoughts, all of which are fundamentally perishable and transient. Shri Krishna urges us to develop and attitude where we shift our focus from the perishable to the imperishable. In other words, we learn to see the imperishable Ishvara in everybody and everything, including ourselves. We saw earlier that everything and every being is a combination of the kshetra and the kshetrajnya. We now stop identifying with the imperishable kshetra and start identifying with the imperishable kshetrajnya, which is Ishvara himself.
 
So then, this is the correct attitude, the correct vision, that we should develop. We are a product of Ishvara and Prakriti, therefore we should identify with the Ishvara aspect as our self, our "I". In parallel, everything and everyone is also a product of Ishvara and Prakriti, therefore we should emphasize the Ishvara aspect which is present in everyone equally. We will come to the conclusion that the Ishvara aspect in us is the same as the Ishvara aspect in everyone else. Shri Krishna says that one who develops such a vision, one who sees the imperishable in the perishable, he truly sees, not anyone else.