Is God the Author of Sin?

This is an excerpt from an appendix in John Piper's book Desiring God. I must admit the same questions have plagued my mind, and by God's will, with the help of Jonathan Edwards, Piper clears the fog.

Is God the Author of Sin? Why does God ordain that evil exist?
Edwards answers, "If by 'the author of sin,' be meant the sinner, the agent, or the actor of sin, or the doer of a wicked thing...it would be a reproach and blasphemy, to suppose God to be the author of sin. In this sense, I utterly deny God to be the author of sin." But he argues, willing that sin exist in the world is not the same as sinning. God does not commit sin in willing that there be sin. God has established a world in which sin will indeed necessarily come to pass by God's permission, but not by His "positive agency."
God is, Edwards says, "the permitter...of sin; and at the same time, a disposer of the sate of events...for wise, holy and most excellent ends and purposes, that sin, if it be permitted...will most certainly and infallibly follow."
He uses the analogy of the way the sun brings about light and warmth by its essential nature, but brings about dark and cold by dropping below the horizon. "If the sun were the proper cause of cold and darkness," he says, "it would be the fountain of these things, as it is the fountain of light and heat: and then something might be argued from the nature of cold and darkness, to a likeness of nature in the sun." In other words, "sin is not the fruit of any positive agency or influence of the most High, but on the contrary, arises from the with-holding of his action and energy, and under certain circumstances, necessarily follows on the want of his influence."
...God doesn't will sin as sin or for the sake of anything evil; though it be his pleasure so to order things, that he permitting, sin will come to pass; for the sake of the great good that by his disposal shall be the consequence.

The rest of the appendix goes on to describe why God has ordained that there be evil at all. Edwards holds that God "wills that evil come to pass...that good may come of it." and continues "There would be no manifestation of God's grace or true goodness, if there was no sin to be pardoned, no misery to be saved from. How much happiness soever he bestowed, his goodness would not be so much prized and admired."

In summary, what I am able to conclude is that if we weren't exposed to evil and sin, we would not be able to truly value and treasure knowing a God where there is an absense of all the things we abhor. We bit the apple, and we can know good and evil. But God's plan was that by knowing evil we can better delight in the good. If all our lives all we had to do was turn on the faucet for water, we would not treasure the faucet as we would if all other times we had had to druge buckets of water uphill from the creek. So by being exposed to what is anti-God, we can appropriately treasure the supreme Goodness this is God.
This has cleared up a whole lot for me. I pray that anyone else who may be struggling can find some truth here too.