"The stuff of life...."

I always cringe when I hear this phrase, as it sounds so sappy...but I suppose in the case of organic molecules it's true. Sort of.
It is true that all of the basic structures of living things are organic--complex compounds composed primarily of carbon, oxygen, hydrogen, and nitrogen--but they are not alive in the sense a total organism is.

These are simply the most abundant small, highly reactive atoms in our corner of the universe. Life, something "more" than just molecules, used the existing material to its benefit. But "the building blocks of life"--another commonly used, sappy expression--just like bricks, is no more life than a brick is a house.