Imagine something you like to eat. Your favourite food. Now, imagine yourself eating nothing but that favourite food, for eternity.

You have not experienced anything except that favourite food, you cannot imagine anything other than that favourite food at all. Would the food taste good to you?

Now suddenly, a new element is introduced into your life. A shit-burger. It is awful. Terrible. Disgusting.

Now you know, what is good and what is bad. You've eaten of the tree of knowledge of good and evil, so to speak. As it turns out, that tree was a shit-burger. The apple, simply a metaphor.

And your experience of your favourite food has been given depth. You may even find that you crave a shit-burger now and again, just to remind yourself that your favourite food is good.

Is the shit-burger "bad"?

In the same way, is Satan "bad" or does he give our experience depth and texture?

Satan is an aspect of God and we should be grateful for his existence. The existence of the "opponent", the "adversary" gives our existence richness and depth.

An existence without "him" would be quite bland and tasteless. If the shit-burger was taken from you never to be returned, you would miss it I think.