Expound on that
You'd have to research it for yourself to be sure.
But I remember reading years ago about these two entities. If you think about it, they are not even described the same. Satan - meaning "adversary" - is often described as a horned creature (think like Pan in Greek mythology) dwelling in a hot place (inside the earth, perhaps), though, interestingly enough, I remember reading about hell as being a place of extreme cold, darkness and desolation. I think the notion of cold hell existed first but I could be mistaken.
On the other hand, Lucifer, the morning star, is often described as beautiful, associated with Venus, I believe. It kind of seems like Lucifer could have even been female actually, but I'm not trying to start anything. Anyhow, the traits of Lucifer are that s/he brings enlightenment. So I never understand how THIS is supposed to be evil. Perhaps it is the additional history attributed to Lucifer which accounts for the negative perception we have.
That being said, I believe any religion/spiritual practice can turn "dark" if the practitioner has not 1) healed any mental and emotional wounds (and we ALL have some) and 2) put the ego in its proper place; the ego is just to be the perspective thru which spirit experiences this life, but it's not supposed to be running shyt.
I think this how you can get a whole group of people who practice a belief system and believe 1) they are "correct" and 2) they have a charge to help others see the way, not thru love, respect and experience but fear, manipulation and control.
Just my thoughts though.