Your business is with action alone; not by any means with fruit. Let not the fruit of action be your motive (to action). Let not your attachment be (fixed) on inaction.
कर्मण्येवाधिकारस्ते मा फलेषु कदाचन। मा कर्मफलहेतुर्भूर्मा ते सङ्गोऽस्त्वकर्मणि॥
Bhagavad Gita 2.47
The same idea in other traditions
And whatsoever ye do, do it heartily, as to the Lord, and not unto men; …
Commit thy way unto the LORD; trust also in Him, and He will bring it to pass.
As a solid rock is not shaken by the wind, wise people falter not amidst blame and praise.
The Master said, "Heaven produced the virtue that is in me. Hwan T'ui—what can he do to me?"
One who performs selfless service, without thought of reward, shall attain his Lord and Master. …
By doing service he acquires the Karman which brings about for him the nâman and gôtra of a Tîrthakara.
Give me the cup! a voice rings in mine ears / Crying: “Bear patiently the bitter years! / For all thine ills, I send thee heavenly grace. …
O ye who believe! Persevere in patience and constancy; vie in such perseverance; strengthen each other; and fear Allah; that ye may prosper.
There is the great Mass (of nature);--I find the support of my body on it; my life is spent in toil on it; my old age seeks ease on it; at death I find rest in it;--what makes my life a good makes my death also a good. …