Those who do more than they are paid for will sooner or later be willingly paid for more than they do.
If you consistently do more than you are paid to do — whether you are a professional, an executive, an hourly worker, or an entrepreneur — you will eventually be compensated for far more than you do. If you give more and better service than those around you, customers will beat a path to your door, and your boss will consider you irreplaceable. With the dearth of outstanding service that exists in the world today, you can instantly differentiate yourself from the competition simply by providing good service.
Source: Those who do more than they are paid for will sooner or later be willingly paid for more than they do.
Eph 6:5-8 Servants, respectfully obey your earthly masters but always with an eye to obeying the real master, Christ. 6 Don’t just do what you have to do to get by, but work heartily, as Christ’s servants doing what God wants you to do. 7 And work with a smile on your face, always keeping in mind that no matter who happens to be giving the orders, you’re really serving God. 8 Good work will get you good pay from the Master, regardless of whether you are slave or free.
(from THE MESSAGE: The Bible in Contemporary Language © 2002 by Eugene H. Peterson. All rights reserved.)