Do you know what Sirius Black said to Harry Potter?

do you know the exact line of Sirius black to Harry Potter? he said these lines when they were in Sirius Black's House in the order of the Phoenix it was something like: " the world isn't just made of good and Death eaters. all of us have a light and dark side what matters is how you act upon it. " something like these words i don't remember the exact words...they were in a room wherein there's a family tree...help please!