Faria was Dantes' mentor and teacher. The years they spent in prison allowed Faria to take Dante under his wing. He is an intellectual, and he teaches Dante everything he knows. They study everything from history to art, and Dante receives his training in language from the man who will leave him his fortune. Abbe Faria also inspires Dante to seek revenge.
Dantes looks after Maximilian in the same way the Abbe looked after him. Maximilian is young and innocent..... and for the most part...... Monte Cristo keeps him that way. He sees Monte Cristo as a father figure, does as he asks, and even agrees to put his life on the line and act as Monte Cristo's second in a duel. Monte Cristo leaves Maximilian (and Valentine) a fortune when they part ways, similar to the way the Abbe left a fortune to Dantes. The difference being that the fortune was not bequeathed.