God is pure love. The creator has always existed. Satan and evil are the result of corruption overtaking a being created with a purpose, it entered Lucifer in Heaven in the very presence of God, through Pride and Iniquity found within.
The inevitable result of Ones Own Choices is what lead to Satan, Demons, Hell, and the Damned.
Satan is not God, God is not Satan, Satan is the entity that rebelled against God to His very face and took 1/3 of the angels with him. He hates God and human beings with every bit of his being, the demons in Hell delight in tormenting the souls there, utterly enjoy it, they are the purest evil possible, they blaspheme God and worship Satan in this unholy dance.
Satan himself says it "I will be as the Most High", he isn't God, he wanted to be LIKE God. He wanted to be the sole object of worship. Since he lost his rebellion and was cast out to a realm of darkness, with his fellow corrupted rebels, the end result, the inevitable conclusion is and always has been pure evil, entirely corrupted irredeemable entities that do whatever they want, whenever they want, to whomever they want to... But they Hate God, they can't hurt Him directly, so they torture us instead, and they're insane, because they owned their corruption and they follow a creed.