Who said "Death is not the end; it is merely a transition."?

This quote is attributed to Professor X.

Death is not the end; it is merely a transition. - Professor X

"Death is not the end; it is merely a transition."

Professor X Death

"Mutants. Since the discovery of their existence they have been regarded with fear and suspicion by humanity."

"We are the future, Charles, not them. They no longer matter."

"Just because someone stumbles and loses their way doesn't mean they're lost forever."

"What we have to fear is fear itself."

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."