What exactly is the "good"?

Yes, this is a very good question. (Ah, but what does that mean?) I am going to assume you are thinking of 'the good' in Plato's thinking, and say that the good is the crowning form in the realm of the forms. The forms are models of concepts and things which have existence in our world. there is a form for 'chair' which is distinct from any particular chair.chairs become chairs by virtue of their participation in the form chair. At the head of this realm of forms is 'the good' Actions are good because they participate in this form.

Is the good another way of talking about God? Yes, but they are not the same thing.

Darkness is the absence of light.

Evil is the absence of good.

Evil does not have to exist for good to exist. This is the beauty of good, it needs no opposite to prevail.

Good is basically positivity. Any progressive thought/action that is meant to create rather than destroy is 'good.'

This article gives a good overview of the philosophical approached to the question of "good", as well as something of a synthesis. It would make a "good" springboard for further study:

http://www.newadvent.org/cathen/06636b.htm

is there such a thing? everything seems like shades of grey to me, i see my friends and m,y not so friends and i wonder if there good or bad, now i think there is no such thing, i walk down my street never muttering ''that old ***** lives in that house, a nice lady lives there'' no no, i say ''someone different lives there, someone more like me lives there'' so there really isn't such a thing as ''good'' i think what we call "good" is simply what we like about orselves, think about this..good things about my personality (to me) is my empathy, my defiance to authority, my intelligence and my compassion, now what do you suppose i think constitutes as a ''good'' person?? an empathic, defiant intelligent and compassionate person of course! what do you like about yourself? or what personality traits do you value most? have you noticed that a lot of the people you like most, if not all, have atleast a few of these traits?

It goes with the bad and the ugly.