I can tell you, with complete belief in the statement I am making, that people are good. Perhaps you will see this instinctively, or perhaps you will come around to this way of seeing things with some fine tuning of your perception. Either way, people are good.
People are good for myriad reasons, but perhaps chief among them is that people want to belong, to relate to others. This desire may be more buried in some than in others, but in the beyond-overwhelming-majority of human beings, this is going to be the case. And maybe this is really what I mean: if you're looking for it, you'll find that folks are offering you all kinds of points of commonality through their different behaviors, and if you recognize those overtures, and respond with respect, you will be amazed at the connections that can result. At base, we're all fumbling in the darkness, hoping that others will find our hand and take it. In that regard, you're no different than your mom or I, or any stranger, no matter how different they might otherwise appear.
And so maybe I'm conflating the concept of "vulnerable" with the concept of "good," but I think there's some value in blurring those two notions. Because I think we perceive goodness in a lot of ways, but at bottom we perceive it as some combination of the ability to confer benefit on us, as individuals, and the absence of threat. And in a lot of ways, when a person makes themselves vulnerable to you, those two elements fall into place.
Now, I don't tell you this so that you'll use the information for self-serving, manipulative purposes. Chances are, if someone makes themselves vulnerable to you, it's because you've done the same for them. The great thing about connecting with another human being is that, when done properly, you've given as good as you've gotten. One of you has found a way in, offered the same to the other person, been accepted and then the two of you achieve some reciprocal emotional benefit (and experience some reciprocal emotional loss). All of that stuff happens in the blink of an eye, mind you, but it happens. What follows next is the free interaction that comes when people have let down (or partially let down) their respective guard.
I realize that this is a lot of wind up for the thesis of this post (that people are good, just in case you've forgotten), but I promise it addresses the point. Few people are completely selfless, and fewer still got out of bed this morning with the express purpose of subordinating themselves to your will and your needs. But people want to connect, and people want to feel valued and feel respected and feel loved (to a greater or lesser degree, mind you, but you can still accept this as a universal truth). The goodness comes from this: if you give that to them -- by reaching out and finding those places to connect with them, emotionally -- you will be astounded by the ways in which they reciprocate. For that matter, you'll also find that there are folks out there who meet you and who know, instinctively, what your projected points of commonality are, and what your needs are. They'll connect with you and all of a sudden you'll find yourself opening up, showing a side of yourself you never do, to a stranger (or maybe just to someone who knows how to play you like a fiddle), and you'll find that you wish this person well, that you want good, good things to happen for them, or at the very least, you will find that you are willing to extend yourself in a way that you normally don't for a stranger.
We want to relate to others, is what I'm driving at. Maybe not every "other," but a lot more than we let on. And the longer you go through life (provided you keep yourself attuned to the world around you) the more you'll find that your ability to connect with people expands. This is largely a function of the fact that your perspective will widen as your experience mounts.
Why does this make people good, you ask? Fair point. Good is a malleable concept here, and as I said before, I'm blurring the line between good and vulnerable. But my philosophy evolved around conflating those two ideas. I've met people who are otherwise bad, who do bad things to good people (or why not..to bad people), but who also had vulnerabilities that they put out into the world, and if you knew what to look for, and accepted and respected what it was that you found, they would treat you with respect and with deference. You also, it is imperative to say, cannot expect every person to be as good as the next. Some of the folks I just mentioned...forget about asking them to spend 99% of their time being anything but cripplingly antisocial. But that 1% of the time that you could connect, you will be surprised at how much it can mean.
So people are good, and some people are better than others. I feel like I've skimped on specifics, here, but maybe that's what's best. You will have a lens through which you view the world, and you will likely find a lot of fault with what I've just laid out, but I want to try and shape the perimeter of your worldview on this issue. I'll let you fill in the details, but at least consider my premise. I didn't come out of the womb with this idea or anything. I didn't consciously try and adopt it, either. It fell into my lap, through repeated years of trial and error. I walked away from it, only to walk back to it. I believe in it, and I hope that in some way it might guide you.
A final thought: whatever view you have on others, you are good. You don't have to explain or contemplate why or how or to what extent. You are good. No one else and nothing else has any bearing on that fact, and really, that's all you need to know about that.