WARNING: DON'T READ THIS IF YOU WILL BE OFFENDED. In the Satanic Bible, according to Anton LaVey who was the founder of the Church of Satan, the devil is a concept entirely made up by people who are frightened or wanting to scare others into servitude of the "right hand" beliefs. That includes not only those religions serving "God", but also "white magick" and other occult phenomena. Naturally, the book goes much further in depth on the subject, but that was what I gathered when I read it.
I'm not saying I agree with the statements I've quoted below, I'm just answering the question.
Please note, I myself am not a Satanist, and so cannot give a full-out explanation about Satan or Lucifer, but I can share what I've read.
Below are the 9 Satanic statements, written by the founder of the Church of Satan, quoted directly from Anton LaVey's book. Many modern day Satanists agree with the following nine statements. AGAIN, I AM QUOTING ANTON LAVEY, THESE ARE NOT MY OPINION. IF THIS INSULTS YOUR RELIGIOUS BELIEFS TOO MUCH, PLEASE STOP READING.
"THE NINE SATANIC STATEMENTS.
1. Satan represents indulgence, instead of abstinence!
2. Satan represents vital existence, instead of spiritual pipe dreams!
3. Satan represents undefiled wisdom, instead of hypocritical self-deceit!
4. Satan represents kindness to those who deserve it, instead of love wasted on ingrates!
5. Satan represents vengeance, instead of turning the other cheek!
6. Satan represents responsibility to the responsible, instead of concern for psychic vampires!
7. Satan represents man as just another animal, sometimes better, more often worse than those that walk on all-fours, who, because of his 'divine spiritual and intellectual development,' has become the most vicious animal of all!
8. Satan represents all of the so-called sins, as they all lead to physical, mental, or emotional gratification!
9. Satan has been the best friend the church has ever had, as he has kept it in business all these years!"
Anton LaVey also says that Lucifer was a Roman God, the spirit of air and personification enlightenment.
To learn more, read up on Satanism and what it means. As with many religions, there are so many different beliefs and interpretations, and you have to form your own educated opinions.
Again, I am very sorry if anyone is upset by this article.