By being loyal servant of the Lord,
you can add to your future inheritance.
Check out Collosians 3:23-25 to see what I mean:
Whatever you do, work at it with all your heart, as working for the Lord, not for men, since you know that you will receive an inheritance from the Lord as a reward. It is the Lord Christ you are serving. Anyone who does wrong will be repaid for his wrong, and there is no favoritism.
It is a general principle of Scripture that a faithful person can earn rewards and add to his or her already-awesome inheritance.
But it should also be noted that God does not play favorites: the loyal will receive extra rewards; the disloyal will receive nothing.
The whole system is based upon keeping the faith.