Well the reality is. God and Satan are both a creation of the mind of man.
In order to evaluate something there must be a base. We think in opposites.
Good/Evil, God/Satan, etc.
It's a by product of living on an earth made of opposites.
Opposing poles, Night/Day, hot/cold, life/death.
You can't say something is good if there isn't something evil to base your judgement on.

