The point, which can hardly be repeated too often, is that differentiation is not separation. The head and the feet are different, but not separate, and though man is not connected to the universe by exactly the same physical relation as branch to tree or feet to head, he is nonetheless connected - and by physical relations of fascinating complexity.
Those people who develop the ability to continuously acquire new and better forms of knowledge that they can apply to their work and to their lives will be the movers and shakers in our society for the indefinite future.
It's the action, not the fruit of the action, that's important. You have to do the right thing. It may not be in your power, may not be in your time, that there'll be any fruit. But that doesn't mean you stop doing the right thing. You may never know what results come from your action. But if you do nothing, there will be no result.
It is our own mental attitude which makes the world what it is for us. Our thought make things beautiful, our thoughts make things ugly. The whole world is in our own minds. Learn to see things in the proper light.