Err, i don't think you can call atheism a religion- that's kinda the whole point! And way more people have died as a result of Christianity than either.
I'm guessing this is in the perspective of a Christian. I'm Atheist and you don't see me pressing my beliefs on you. You don't see me meddling in your affairs. And it is not supposed to be "more worst" it is just "worse".
And what are you even asking?
I only see one religion there; atheism is the complete lack of theistic belief in god, not religion. Besides Christians cause more problems than us atheists. Trust me. You haven't an idea how frustrating Christians are.
By far Satanism...
Atheism is just pure ignorance
Satanism is worshiping the being that's only purpose in life is to turn people away from God's embrace. Their person of worship deceives lies and is the reason for all of the bad in the world. Atheism is not acknowledging (spelling) the devil or any God.
I disagree strongly with both of them, especially satanism. And to me, Satanism makes no sense at all. If you believe in Satan, then you must believe in God. And why would anyone want to willingly follow Satan when all of God's amazing blessings are offered right in front of them??
Why do some theists call Atheism a religion as if it is supposed to somehow be insulting.
I mean, I know they don't literally know the definition of the word, but it always seems that when they try and call Atheism a religion, they're trying to use it as an insult.
I don't think either one is bad. But if I had to pick which ones worse than the other, I'd have to say Satanism, but only because its followers tend to dress a little funny.
As a Christian I would prefer to see atheism prevail over Satanism as at least then the person has a better chance to convert as they have more freedom.