Lucifer

Where did Lucifer get the idea of what is "bad" if he was also in heaven, a high ranking angel in a place of all that is good and holy? A place where there is supposedly no "bad"? 

Firstly, what factor/s determines your acceptence into heaven? There is no one or few things that determine this but their is for hell? 

We as people "sin" because we see these actions from others, so who or what was Lucifer emulating?