Merit is what is earned. It is that which entitles the doer of good work to receive a reward or payment for a service or action.

In Roman Catholicism, “By merit (meritum) in general is understood that property of a good work which entitles the doer to receive a reward (prœmium, merces) from him in whose service the work is done.”¹Catholic Encyclopedia, merit, newadvent.org/cathen/10202b.htm