"We are what we repeatedly do."
That is a hard saying to hear. It is especially difficult if the things you repeatedly do are not good things.
One of the wonderful things about the gospel is that true change can happen. Psalm 19:7 states, "The Law of the Lord is perfect converting(transforming) the soul(the nephesh - the inmost being)". God's word is so complete that it can transform you at your very core.
This is why Paul states in one of his epistles, "... and such were some of you." (I Cor. 6:9-11) That is what we were!
In other words... You can go to an AA meeting and instead of saying, "Hi. My name is ________ and I'm an Alcoholic..." you can say, "Hi! My name is _________ and I'm NOT an Alcoholic... I used to be, but not anymore!"
Praise God for new identities!
With all of that said, I still agree with Aristotle. I just believe that the thought shouldn't end there.