Well, I have a few of my own favorites. One is when Abbe Faria and Edmond are digging and Edmond tells the Abbe:
"I don't believe in God,"
and Faria replies,
"It doesn't matter, he believes in you."
We see by the end of the novel that God has been with Edmond and the biggest lesson he learns after trying to avenge himself against everyone is that vengeance belongs to God. All it does to man is destroy him. Edmund, thankfully, learns this lesson.
Another one I like is when Abbe Faria asks Edmond for help digging. He tells him he will offer Edmund something in return. Edmund asks,
and the Abbe says,
"No, freedom can be taken away, as you well know. I offer you my knowledge."
He then proceeds to teach Edmund everything he knows, transforming Edmund from an uneducated sailor into a highly educated man that speaks many languages, can read and write like a poet, etc.
Finally, there is this one, at the end of the novel:
“Until the day when God will deign to reveal the future to man, all human wisdom is contained in these two words,—‘Wait and hope.’”
This summarizes the lesson that Edmund Dantes learns - that man should let God take care of vengeance, and that man's job is to wait and never give up hope.
An awesome novel, huh?
"all human wisdom is contained in these two words"