There are alot of ways and alot of theories about what "good" is and how to be good or do a good thing.
To be good is a relative word, something that we can interpret in may ways.
Let's explore "good" and let's see why a doctrine of good is necesary.
Good is proportional to the scarcity, the less material things one has, the more good the person is.
Good deminishes proportionally the more material things one has. The more the wealth the less the good.
But what is exactlly good? I would define good as an action or a deed that for the one performing it does not result in finnancial, material or other gains and the receiver gets an immediate gain or help.
Many good deeds are considered good but they do not qualify for the doctrine of good.
Example, you get help at the city hall, but you have to pay for it. The oeople at city hall do a good deed but ask for a fee, that is a finnancial gain. That is not a genuine good deed.
You got to the city hall, you need help, clerk helps you with what you need without asking for a fee. That is a genuine good deed.
Now people will jump saying that that is not good for the cityhall, the fee covers the costs. A one time fee of a few dollars does not cover the costs of running a city hall.
We as citizens pay tax to explicitely the purpose of having a city hall cover its expenses. Everything above that is greed.
Still people will think, how is the city hall going to make a profit? A city hall is not a business, it is a democratic body that is put in place for serving the citizens. How can an entity serve its subject by asking for a fee?