How should we live in this world?

Bhagavad Gita teaches us to live in this world without getting attached to anything or any being. Just like a drop of water on Lotus, where though it is there on lotus but it is not attached to it.

Bhagavad Gita Chapter 5

TEXT 10

brahmany adhaya karmani 
sangam tyaktva karoti yah 
lipyate na sa papena 
padma-patram ivambhasa


 SYNONYMS
brahmani--the Supreme Personality of Godhead; adhaya--resigning unto; karmani--all works; sangam--attachment; tyaktva--giving up;karoti--performs; yah--who; lipyate--is affected; na--never; sah--he;papena--by sin; padma-patram--lotus leaf; iva--like; ambhasa--in the water.

TRANSLATION
One who performs his duty without attachment, surrendering the results unto the Supreme God, is not affected by sinful action, as the lotus leaf is untouched by water.


So, we should try to live in this world unattached & devote our mind towards Krishna as then, though living in this world, our mind will be unattached to the things and beings of this world.