The truth is that you cannot attain God if you have even a trace of desire. Subtle is the way of dharma. If you are trying to thread a needle, you will not succeed if the thread has even a slight fiber sticking out.
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.
As a toy fruit or a toy elephant reminds one of the real fruit and the living animal, so do the images that are worshipped remind one of the God who is formless and eternal.
The rishis of old attained the Knowledge of Brahman. One cannot have this so long as there is the slightest trace of worldliness. How hard the rishis laboured ! Early in the morning they would go away from the hermitage, and would spend the whole day in solitude, meditating on Brahman. At night they would return to the hermitage and eat a little fruit or roots. They kept their mind aloof from the objects of sight, hearing, touch, and other things of a worldly nature. Only thus did they realize Brahman as their own inner conciousness.
Common men talk bagfuls of religion but do not practise even a grain of it. The wise man speaks a little, even though his whole life is religion expressed in action.