Assuming, as you grow older, that you're the guardian of the world's wisdom, even if you haven't necessarily lived enough to know what's right and wrong.
The world is being created and destroyed in this very moment. Whoever you met will reappear, whoever you lost will return. Don’t betray the grace that was bestowed on you. Understand what is going on inside you and you will understand what is going on inside everyone else. Don’t imagine that I came to bring peace. I came with a sword.
If we are willing to act violently in pursuit of a peripheral interest, everyone can be certain that, when a vital interest is at stake, we will be still more violent. 'Credibility' is defined as the willingness to kill a lot of people now for a not very good cause to assure the world that we'll kill a lot more people if we can find a better one.