People say that Lucifer had to Fall to introduce Evil to the Earth. If that is true, that means his alternate plan had to be introduced, and God created at least one Spirit to Fail. And by fail I mean that spirit would never have any chance at redemption, and would have to be predestined to Outer Darkness.
I believe Truth transcends God, our Heavenly Father. I believe He is subject to Truth, and that He derives his knowledge and power from adherence to Truth. I interpret Alma 42:13 in a similar light. God is subject to the Law of Justice, and the consequence of failing to observe this law is the loss of his knowledge and power. I am not sure of the mechanics that govern Truth, nor am I sure of its origins. I think that Truth is universal law that ultimately must be yielded to.
If Truth transcends God, then Evil must transcend Lucifer. Lucifer was tempted in the Pre-Existence. In fact, he was probably only doing that which has been done before. In our world, Lucifer's pride caused him to give in to that temptation. However, if he had resisted, then Evil would have found another way to introduce temptation into our world. Even if EVERY spirit child of our Heavenly Father chose to follow God's Plan of Salvation, God's Plan would not have been interrupted. Evil would have tempted Adam and Eve, they would have Fallen, and we would all have the choice to return to God. Evil had to be present in our world to tempt us. If it were not so, then we never would have had the chance to choose Truth, and therefore choose our Heavenly Father.
By recognizing that sin would have entered our world regardless of Lucifer's (or any other's) actions, I find comfort that God didn't create us with one (or many) automatically consigned to an eternity of separation. I think that saying Lucifer's fall was necessary for the Plan of Salvation limits his Free Agency. If God limited Lucifer's Free Agency, then that means our own Free Agency is limited. Free Agency is one of those concepts that must apply to everyone. It is a constant gift. If God were to limit anyone's Free Agency, then none of us could count on receiving it either.
A friend pointed out that this theory still doesn't answer why God doesn't "miracle [Satan] out of existence?" unless he serves a purpose. God does have the ability to use those that fight against Him for His purpose. I am not saying that God causes those who fight against Him to act that way, or that He wants them to. I just think that regardless of each individuals decisions, God can (and does) use the results in the best way possible for all his children.



