Here is the full quote:

The Don had proceeded to instruct him. "There are men in this world," he said, "who go about demanding to be killed. You must have noticed them. They quarrel in gambling games, they jump out of their automobiles in a rage if someone so much as scratches their fender, they humiliate and bully people whose capabilities they do not know. I have seen a man, a fool, deliberately infuriate a group of dangerous men, and he himself without any resources. These are people who wander through the world shouting, 'Kill me. Kill me.' And there is always somebody ready to oblige them. We read about it in the newspapers every day. Such people of course do a great deal of harm to others also.

"Luca Brasi was such a man. But he was such an extraordinary man that for a long time nobody could kill him. Most of these people are of no concern to ourselves but a Brasi is a powerful weapon to be used. The trick is that since he does not fear death and indeed looks for it, then the trick is to make yourself the only person in the world that he truly desires not to kill him. He has only that one fear, not of death, but that you may be the one to kill him. He is yours then."

It was one of the most valuable lessons given by the Don before he died, and Michael had used it to make Neri his Luca Brasi.

An excellent speech, one that I'm quite disappointed did not make it (in some form) into the film.

Signor V.