These people are like ... a frog living in a well, who has never seen the outside world. He knows only his well, so he will not believe that there is such a thing as the world. Likewise, people talk so much about the world because they have not known the joy of God.
Take the case of the infinite ocean. There is no limit to its water. Suppose a pot is immersed in it: there is water both inside and outside the pot. The jnani sees that both inside and outside there is nothing but Paramatman. Then what is this pot? It is 'I-consciousness'. Because of the pot the water appears to be divided into two parts; because of the pot you seem to perceive an inside and an outside. One feels that way as long as this pot of 'I' exists. When the 'I' disappears, what is remains. That cannot be described in words.
One man may read the Bhagavata by the light of a lamp, and another may commit a forgery by that very light; but the lamp is unaffected. The sun sheds its light on the wicked as well as on the virtuous.
To work without attachment is to work without the expectation of reward or fear of any punishment in this world or the next. Work so done is a means to the end, and God is the end.
You speak of doing good to the world. Is the world such a small thing? And who are you, pray, to do good to the world? First realise God, see Him by means of spiritual discipline. If He imparts power you can do good to others; otherwise not.
Meditate upon the Knowledge and Bliss Eternal , and you will also have bliss. The Bliss indeed is eternal, only it is covered and obscured by ignorance. The less your attachment is towards the senses, the more will be your love towards God .
As a boy holding to a post or a pillar whirls about it with headlong speed without any fear or falling, so perform your worldly duties, fixing your hold firmly upon God, and you will be free from danger.
Dwell, O mind, within yourself; Enter no other's home. If you but seek there, you will find All you are searching for. God, the true Philosopher's Stone, Who answers every prayer, Lies hidden deep within your heart, The richest gem of all. How many pearls and precious stones Are scattered all about The outer court that lies before The chamber of your heart!