And whatsoever ye do, do it heartily, as to the Lord, and not unto men; …
και παν ο τι εαν ποιητε εκ ψυχης εργαζεσθε ως τω κυριω και ουκ ανθρωποις
Colossians 3:23
The same idea in other traditions
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.
The Master said, "A minister, in serving his prince, reverently discharges his duties, and makes his emolument a secondary consideration."
Whatsoever thy hand attaineth to do by thy strength, that do; for there is no work, nor device, nor knowledge, nor wisdom, in the grave, whither thou goest.
That man can have nothing but what he strives for; That (the fruit of) his striving will soon come in sight: Then will he be rewarded with a reward complete;
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.
Earnestness is the path of immortality (Nirvâna), thoughtlessness the path of death. Those who are in earnest do not die, those who are thoughtless are as if dead already.
Tukla, king of Persia, once visited a devotee and said: “Fruitless have been my years. None but the beggar carries riches from the world when earthly dignities are passed. Hence, would I now sit in the corner of devotion that I might usefully employ the few short days that yet remain to me.” The devotee was angered at these words. “Enough!” he cried. “Religion consists alone in the service of the people; it finds no place in the rosary, or prayer-rug, or tattered garment. Be a king in sovereignty and a devotee in purity of morals. Action, not words, is demanded by religion, for words without action are void of substance.”