Is Satan Necessary to God's Plan?

In LDS theology it seems that Satan is seen as playing a vital role in God's great plan of salvation. Many people find this idea troubling.

As I have studied the idea of "opposition" and the plan of salvation I, too, have questioned how vital Satan is to that plan. There are two key reasons I have to wonder if he really is necessary.

*It appears to me that opposition exists with or without the influence of Satan
*If he is actually carrying out God's plan, why would he be punished for it?

Now, opposition is a big topic all by itself. I have studied it and discussed it with others and it is really an interesting topic.

First, I think we use the word "opposition" in two ways. 1) the act of opposing, resisting or combating. 2) the state of being opposite (ex. black and white are opposite).

Satan seems to fall under the first definition of opposition. When we think of good and evil we think of opposing forces. Two armies fighting against one another. I think I can argue that this is not necessary to God's plan of happiness.

The second type of opposition we talk about is very natural. In heaven, before we came to earth, it appears that we had agency. If this is true, we also had opposition. At least, our theology tells us that we can't have agency without oppostion. Right? Agency and opposites just seem to be a fact of the universe to me.

If one takes the creation story literally, God made sure this earth contained lots of opposition. He put two opposite trees in the Garden. One would bring everlasting life and the other death. Satan tells Eve that she must eat the fruit of knowledge of good and evil. He is also the one who tells her this is the only way to bring about God's plan (basically). Was Satan telling her the truth??? Why would God set them up like that? Isn't Satan the author of lies, fear, guilt and shame? Would a loving Father set up his children for death?

Alright, I'm getting distracted with too many questions. I hope the reader can fully understand my quandry.

It appears to me that opposition is part of the order of the universe. Opposites don't have to be bad. In fact, they are all true. Black is just as true as white. Is one bad and one good? I don't think so. Cold is the opposite of hot, and I prefer a mixture of the two. We also have pleasure versus pain. But are either one of them all good or all bad? No. They both can be physical, mental or spiritual states of being. There are people who are addicts of pleasure and those addicted to pain. I find it interesting that we want to label everything as good or evil. Why do we have that desire?

OK, the real thing that got me thinking about the necessity of ol' Scratch is this:

Little children are not tempted by him. They are out of his reach! Until when??? Until they are TAUGHT right from wrong! Could that be when they "partake of the forbidden fruit?"
Have we not been told to "be like little children" in order to inherit the Kingdom of God?

Also, Satan is to be bound for 1000 years during the Millenium. He will be bound by the righteousness of the people. But, opposition will still exist under definition #2. In fact, life may go on fairly similar to how it is now but the people will have NO DESIRE to sin.
If Satan was necessary for the Plan of Salvation, then how could he be bound for 1000 years while people are still being born? How does that effect The Plan in their lives? We learn that there will be no sorrow because there will be no death-people will get "twinkled" when they are old.

So, do we really need a Satan at all? Why don't we all just kick him out right now? Instead of fighting him, why don't we just reject him?

We all laugh at Satan for being so stupid and falling right into God's plan, however, he might be laughing at us for being so delusional.