What is one argument Tim O'Brien is making about the living?

From the text:

All around you things are purely living, and you among them, and the aliveness makes you tremble. You feel an intense, out-of-the-skin awareness of your living self—your truest self, the human being you want to be and then become by the force of wanting it. In the midst of evil you want to be a good man. You want decency. You want justice and courtesy and human concord, things you never knew you wanted. There is a kind of largeness to it, a kind of godliness. Though it's odd, you're never more alive than when you're almost dead. You recognize what's valuable.