You may say that that is the case, but if you're responsible for everything, you may as well be responsible for nothing.
No, you are morally responsible for every evil happening right in front of you that you could immediately change with little risk to yourself.
For instance if you can't swim and the child is in the middle of the pond, I'd argue you aren't responsible because the risk is too great to yourself.
In fact due to the danger of drowning people pulling you under, I'd argue unless the child is in water shallow enough for you to stand in it's not your moral responsibility to save them.
Though in the situation, I'd probably feel compelled to save them anyway.
The problem with this is that you snuck a quantitative difference there and made it sound qualitative. How much risk is "little risk"? What if you could spend all your money and save N people from starvation? There's no risk to you, so are you responsible for their deaths if you don't do it?
What if the child is a bit less likely to pull you under? What if even less than that? Where do you draw the line?
You're never completely free of responsibility, there are just varying degrees.
Heroism (jumping in the pond and saving the child) doesn't imply moral responsibility for the situation.
Assuming the full question is:
> Is it not possible to be a passive observer of evil without being responsible to some degree?
No, with the caveats of being mentally and physically able to do something about it of course.
How can you impose a duty to fight evil when "evil" itself has no workable concrete definition?
I am obligated to my family and to myself. To provide for them as an example. But I would also be able to fly across the world and feed a starving child, in theory. But my obligation to my own family, and myself outweighs that. There would also be risks to the journey. Consequences with those actions as well.
If you say that proximity does not imply morality, where are you drawing the line? Would family friends and job duties encompass it? Certainly you can’t say that helping your child implies you are responsible for the whole world.
That is my personal take on it. We are all living in sin, in reality we are all full of shit and have only a veneer of ethics.