Why does God let Satan fool with people at all? I mean, I understand about free will, but letting him mess with us seems to make us less free to respond to God. What if God had stopped and barred Satan from coming into contact with humans? Does that make sense, or is it muddled?
Also, isn't God going to do away with Satan him in the end times? If so, then why not do away with him now? Even if he's not going to "kill him," I wonder why God lets him "loose."
I think God allows Satan to mess with us in part for the same reason He allows us to mess with each other. If there is to be real love, there must be real free will; but if there is to be real free will, then our wrong decisions must have real consequences for us and for other people. You know, men and angels both were given free will, and Satan is just a fallen angel. Over the centuries, many other possible reasons have been suggested. For example, if God did not allow even the possibility of evil, then perhaps we would have no chance to experience great goods like the virtue of courage.
I don't know what would have happened if Satan had been barred from coming into contact with human beings, but it's possible that we needed to be tempted. Notice that I didn't say that we needed to sin. But if there had never been any temptation — if the possibility of turning away from God had never been presented in a way that made it seem real to us — would our adherence to God really have been freely chosen? Notice that God often allows human beings to undergo trials or tests. The purpose of the test isn't to tell God something about us, because He knows everything. It's to tell us something about us. For a fictional presentation of this view, you may be interested in the novel Perelandra by C.S. Lewis. In the novel, the tempter is trying again, but on a new planet.
Now about your final question — why God doesn't act immediately to put an end to the evil Satan commits against human beings. Though we don't have all of the answer, we have part of it. The crucial thing is that God has already acted against Satan. Remember that Satan's greatest harm to us was in the past, when he led our first parents astray. Ever since then something has been wrong inside the human heart, where Satan established his foothold. God's plan against Satan began to unfold immediately; it was His plan for our redemption. The calling of Israel, the giving of the Law through Moses, the prophecy of the Savior through the Prophets, the coming of Jesus, His atoning death and resurrection, the founding of the Church — all of these things were part of God's plan against Satan.
If you ask why God didn't use a faster-working plan, I suspect that part of the answer is that no faster plan could have succeeded with beings of the kind that we are — beings who have free will and so cannot be "forced" to be good, but in whose hearts the damage of sin had already been done. God could have destroyed Satan at any time, but the sinful bent in our hearts would have persisted. More important than destroying Satan himself was putting an end to Satan's power over us, once and for all.
That's what happened on Easter morning. Jesus' sacrificial death and resurrection on our behalf was the beginning of the end for Satan, because it destroyed his foothold in the contested territory of our hearts. Every human being who turns in repentant faith to Christ the Rescuer dies with Christ to his sins, and is raised in Christ to a new kind of life. Of course this new life takes root only gradually, but as Lewis explained, the entry of Christ into a human heart is like the landing of the Marines on the strategic part of an enemy-occupied island. Once the Marines establish their beachhead, the expulsion of the enemy from the rest of the island is only a matter of time.
We don't fully understand what God has told us about the closing phases of the war. In this phase, however, what we see is that the Marines are landing on island after island — Christ, in other words, is establishing his dominion in heart after heart. The timing for God's destruction of Satan is merely one small part of his larger plan for uprooting the evil done by Satan in our souls. God could have merely destroyed Satan but let the sinful tendencies in our hearts persist. In His compassion, He attacked sin at the root. I think this is more glorious still.
In the meantime, Satan is allowed to do no harm that God has not foreseen and provided for. God still allows us to be tempted — but He has promised that so long as we remain in His will, He will not allow us to be tempted beyond our power to resist. By permitting lesser temptations, He instructs us, "for the Lord disciplines those He loves" (Hebrews 12:6, RSV). In this way, even the Enemy's attempt to do harm is turned by God into a means of our good.
Grace and peace,
Copyright 2003 Professor Theophilus. All rights reserved.