As an atheist, I don’t believe in Satan/Lucifer, but the character as a rebellious figure has some appeal. I think a lot of atheists agree. The Church of Satan is a just a group of atheists who admire the figure and want to piss off Christians. Now, Satan wouldn’t be a just leader, but on the other hand, neither would God. The only reason God is good is because God is first and gets to define what good is for his people. This is not good as humans, specifically modern Westerners, would typically define morality. I find a Doctor Who storyline to inadvertently illustrate God’s tyranny and why an Adversary would be attractive.
The 2007 Doctor Who season involves the Doctor’s evil counterpart the Master taking over the Earth, and there’s a parallel to God fighting Satan, with the Doctor as God and the Master as Satan. The Master takes away the Doctor’s strength, but his companion Martha Jones induces the entire planet to think the Doctor’s name/title at once, which causes him to regain his strength. Even after everything, the Doctor has mercy in his heart for the Master and forgives him. With this theme of prayer and the Doctor being the honorable defender of the human race, the analogy seems clear. I’d like to offer a different comparison.
Most people, growing up with the Christian understanding of God as a benevolent figure, can’t understand why atheists find the Satan character appealing and make assumptions about atheists being evil and worshiping Satan because God is goodness and the Adversary is evilness. Well, here’s my take: The Master is God. He rules on high, sends troops of super-powerful otherworldly soldiers to impose order on the world through mass killing, destroys cities and whole civilizations should they offend him, and generally treats people like playthings. The worst rebels are taken from the Earth to suffer at his hands, torturing one to the point of death only to be revived and tortured again in an ongoing cycle. The Doctor is Satan, believing the Master doesn’t have the right to rule the universe, and he leads a rebellion. It’s not a perfect analogy because Satan doesn’t have humanity’s best interests in mind and the rebellion is selfishly motivated, but insofar as the Master ruling with an iron fist there is sufficient similarity to God.
Suppose the Master’s reign lasted more than a year. Suppose it lasted several decades at least. After a time, the human resistance would lose its spirit because freedom stops being the normal state and it becomes normal to be slaves to the Master. The Master would have his people repeat the story that the Master being in charge is the natural way of life. People would hear this constantly and be forbidden to challenge it. Children born to this world would just accept it as natural. His followers would come to regard him as absolute goodness, meaning that anyone who opposed him would be seen as evil. This is how tyrants operate. Hitler and Stalin did and they were hardly the first.
So, even if the Judeo-Christian God were real, he would not be worth worshiping because I deem him as much a tyrant as the Master. God is not goodness personified by any reasonable definition; he merely claims such because he has the power. Morality is subjective and to be defined by people having arguments and conversations with each other. Thus, a rebel like Satan is not necessarily evil because he opposes God. In modern media, Satan is sometimes portrayed sympathetically for this reason or is portrayed as evil but might have a point. I like Supernatural’s take on it where God is compared to an abusive dad and Lucifer has a point, but Lucifer’s still a monster and unable to see the inherent worth in human life, so he must be taken out.
In the end, God and Satan are fictional, but Satan appeals as a heroic figure, daring to defy the holy tyrant God.