There are many versions of truth, only one is obviously correct.
Lets begin with a simple premise.
Unlike Christianity that believes that there is a twin evil brother to God, Judaism and rationality must assume that there is no such thing as evil.
The question, is, how is there evil?
For if God is good then we must say that as all is created by God, all is likewise good.
As our sages teach ein ra yoried limalah evil does not come from heaven.
In other words, assuming that all is good we need to find a reality that can explain all that is bad.
Many religions choose novel approaches but as we are explaining Judaism vs. Christianity let us explain this from both viewpoints.
To say that there is an independent force of evil would be ludicrous for the simple reason that it is basically idolatry.
For the very premise of monotheism is a single God in control of all.
In Judaism, Satan is an angel created by God.
Why not start with that poor rich man called Job.
The Satan challenged God.
“It is not as you say that Job is the greatest of all men.”
“Let me put him to the test and we shall see.”
Now can it truly be that there is a challenger to God?
The Baal Shem Tov explains a truly remarkable thing.
Why is that we need to have a court case after 120 – can’t we trust God’s judgment?
But human nature is different.
If God himself would tell you that you need a single minute in hell you would disagree.
That which is pleasure and that which is painful is immediately rationalized in either direction.
In other words, God himself goes to extraordinary lengths to prove to us that he is right and hence there needs to be an alternative course of action in which we indulge in, in order to discern between the two, that we ourselves using our own senses, experiences and most importantly rational mind, will come as we have come, as you have come if you are reading this words, to realize, that God is good, and that the darkness, the evil, is merely what we need to shun.