Question:
My friend at school asked why God allows swearing and drugs to exist in the world. I told her that it was the devil. She then asked, “If God is so powerful, why does He let the devil do these things?

Answer:
Before we try to determine why God allows evil to exist in the world, let me make a comment about the sins that humans commit and the part that the devil plays in this. We often hear people say, “The devil made me do it,” but the Bible is very clear that men are responsible for every sin they commit. The day is coming when God shall “render to every man according to his deeds” (Romans 2:6). We read in Revelation 20:13, “…and they were judged every man according to their works.” The people, referred to in this verse are all those who died unsaved and who stand before the Great White Throne. They will have their lives evaluated to determine the degree of punishment which they will receive in the Lake of Fire. Now, if the devil were solely responsible for the sins of mankind, God would be unfair in holding men responsible. Thus, we must ask ourselves, “What part does the devil play in all this?”

Ever since the first sin of mankind (in the Garden of Eden), the devil has played the role of the “tempter.” That is, he has been actively seeking to entice men and women (and boys and girls) to, rebel against God’s will for them. And although his influence is great (see John 8:44; Ephesians 2:2; 1 John 5:19 JND version), he can only make suggestions to the human heart to sin (as he did with Eve in the garden). In other words, HE CAN’T MAKE US SIN. When people swear, or use drugs, (as you mentioned in your question), the devil may be an outside agent alluring people to do this, but they are responsible for responding to the temptation to do evil. I might just mention that there are some cases where people have given themselves over totally to the influence of the devil and the result has been demon-possession (Judas Iscariot furnishes us with a good example of this—see John 13:2, 27). But those people will still not be able to say on the day of judgment: “The devil made me do this,” because had they not put themselves into Satan’s hand, he could not have done anything.
Now to the main question, “Why does God allow evil to exist in the world?” This is a good question, and one that men have been asking since the Fall of Man in the Garden of Eden. We see over and over again in the Bible that God is “omnipotent” (which means “all-powerful”), so why doesn’t He stamp out all of the evil men in the world and crush the power of Satan? Let us be assured of this; God able to do this, and one day He will put an end to all of the wickedness that prevails in the world. We saw earlier, from Revelation 20:13, that God is going to judge the evil works of kind, and we then read, “Whosoever was not found in the book of life was cast into the Lake of Fire” (vs. 15). And earlier in that same chapter we see Satan doomed to the same eternal judgment (vs. 10). So then, God will eventually make a total end of sin, by confining all sinners to the Lake of Fire. This assures us that God not indifferent to evil. His holy nature HATES sin and thus we read in Psalm 7:11, “…God is angry with the wicked every day.” Just think, EVERY DAY, for nearly 6,000 years, God has been angry with the wicked. So why doesn’t He end it now?
I believe the answer to this lies, in part, to God’s many plans which He purposed before time even began. All of these plans revolve around His Son (see Ephesians 3:11). He has planned for His Son to have an earthly kingdom which would involve an earthly people [Israel] as the center of His kingdom. He has planned for His Son to have a heavenly people (the Church) which will share, as His eternal bride, in His glories all eternity. (God’s wondrous plan is shown in a chart: “A Chart on the COURSE OF TIME FROM ETERNITY TO ETERNITY.) To accomplish all of these purposes, there is so much time needed to bring them about. God has His calendar of events and everything is running according to His perfect schedule. Until all God’s plans are completed, He is allowing man (and the devil) to pursue their evil course. But let us remember that He HATES their sin, and it is only His grace which bears with them. While men and fallen angels rebel, God is bringing men and women to repentance, saving their souls for all eternity. Second Peter 3:9 is especially illuminating regarding this, “The Lord is not slack concerning His promise [the promise of judgment—vs. 7], as some count slackness; but is LONGSUFFERING TO US-WARD, NOT WILLING THAT ANY SHOULD PERISH, BUT THAT ALL SHOULD COME TO REPENTANCE.”So we see that God’s allowance of evil is not due to any lack of power on His part to subdue the wicked, and it is not due to any indifference in God’s heart, but that it is due to His all-wise plans which are being worked out in the process of time, and these plans include the eternal salvation of precious, immortal souls. And let us remember that, even though men and angels are allowed to sin, they are still limited in what they can do, and their judgment day is coming. The day is coming (like in the days of Noah) when God’s longsuffering will end and sinners will experience God’s wrath against their sin (see Acts 17:31). Until that day, the battle between good and evil rages on, with Satan seeking to keep the souls of men in spiritual darkness, and with God seeking to bring the light of the gospel into men’s hearts so that they may be delivered from Satan’s influence, and from the evil of their own hearts.