[lelio]

But if man is only truly alive and good when he is true to himself and his virtue, how can evil exist?
Evil exists as it is the opposite of advancing man's life. For example, socialism is evil as it forces me to work for the good of the whole. That came from man's mind and not from a religious standpoint, to answer your question where it came from.
In the words of Francisco D’Anconia (I love this character, btw), “Contradictions cannot exist.” Good and evil contradict one another. The presence of both in this world is clearly a contradiction.
As we are all individuals (you are all individuals! -- MP) you have the ability to be good or evil. I can't see the actions of the individuals being a contradiction.
I think what Francisco was getting at was that you, as a robber, can't pretend to live in a free and virtuous society.

[yendu bwam]

For example, socialism is evil as it forces me to work for the good of the whole.

So goodness is about selfishness (not working for the good of the whole)?