Did the envy, lust and gluttony just wanted to become human in FMA?

Did they do all does horrible things just to get the stone to be human, or do they just want to take over the world or something because i heard lust say they wanted to become human, after they become human would they just abandon their evil ways and live their on life or would they just continue to try and kill edward and the military? i know a lot of questions in one sorry, but please answer them as best as you can