If there were enough stuff, there would be nothing you would have to do to get whatever it was that you wanted or needed. You would just reach out and it would be there. But that is not how humans decided that it is. They said, there is not enough. So now they faced the question: How does one get enough? How does one qualify?
You imagined that there must be something that you had to do in order to get the stuff of which there was not enough— something that would allow you to lay claim to it without argument. This is the only way that you could figure out how to get everything—including God—divided in your favor without killing and squabbling.
You imagined this to be the Requirement.
You told yourselves that fulfilling it—whatever it was— is "what it takes." That idea has held firm to this very day. If anything, it has grown stronger. You believe that when you do the things you need to do, you can be the things you want to be.
If you want to be happy, if you want to be secure, if you want to be loved, then there are things you are going to have to do. You cannot be these things unless you have enough. And you cannot have enough unless you do what it takes to get enough—to qualify for enough.
This is what you believe, and because you believe it, you have elevated doing to the highest place in your cosmology.
Even God says there is something that you have to do in order to get into heaven.
This is how you have it put together.
This is the Requirement.