Satan was never God nor a god. He is a fallen angel, and is failure-bound.

For more info:

https://www.ligonier.org/learn/devotionals/victory-over-satan

Satan is no longer the "ruler" of the world, that ended with Christ's death on the cross. He still prowls about. To be clear, he was never God nor a god. He is a fallen angel, and is failure-bound.

For more info:

https://www.ligonier.org/learn/devotionals/victory-over-satan