The age-old question of where and how sin began has been explored and debated by some of the greatest minds of history, yet no one can give a completely definitive or satisfying answer. Some, quoting Isaiah 45:7, seek to make God the author of sin: “I form the light, and create darkness: I make peace, and create evil: I the Lord do all these things” (KJV). However, the KJV’s word evil, from the original Hebrew rah, is better translated as “calamity.” The context of this passage concerns God’s sovereignty over natural disasters. God is sovereign over all things (Exodus 4:11), but He is not the author of sin (1 John 1:5; cf. James 1:13). He hates sin (Proverbs 8:13). Moral evil originated with the creature, not the Creator.
John Calvin wrote, “The Lord had declared that ‘everything that he had made … was exceedingly good’ [Genesis 1:31]. Whence, then comes this wickedness to man, that he should fall away from his God? Lest we should think it comes from creation, God had put His stamp of approval on what had come forth from himself. By his own evil intention, then, man corrupted the pure nature he had received from the Lord; and by his fall drew all his posterity with him into destruction. Accordingly, we should contemplate the evident cause of condemnation in the corrupt nature of humanity—which is closer to us—rather than seek a hidden and utterly incomprehensible cause in God’s predestination” [Institutes, 3:23:8]. In other words, sin was not part of the original creation, nor was it decreed by the Creator’s will.
The first man, Adam, sinned, and his transgression spiraled mankind into sin, but this was not sin’s origin. Ezekiel 28:13–15 speaks figuratively of Satan, who was originally created without flaw, as all things created by God were. Verse 15 gives us a hint as to the origin of sin: “You were blameless in your ways from the day you were created till wickedness was found in you.” Isaiah 14:12–14 further indicates that Satan (Lucifer) sinned in his pride and his coveting of God’s throne. When he rebelled against God, Satan was ejected from heaven (Ezekiel 28:15–17; cf. 1 Timothy 3:6).
Which brings us to the question, how did evil manifest itself in a perfect creature? It may be good to mention that evil is not a created thing—it is not a creature and has no independent being. Also, evil has no standard as goodness does; it is a lack, a deficiency, a falling short of the standard of God’s perfect goodness. All sin, no matter how trivial it may seem, falls short of moral perfection. God is always consistent with His perfect nature (Deuteronomy 32:4). All sin, therefore, must come from the creature, and the desire for evil comes from within the creature (James 1:14–15). Sin was “found” in Lucifer because of a choice that angel made to seek something other than what God had chosen for him. Any time we seek “other” than God’s choice, we sin.
To say sin originated within God’s creatures does not mean God was surprised or caught unaware by it. Although God did not bring about sin, He certainly allowed it or it would not exist, since God is sovereign over all things. It’s true that He could have prevented sin, but that would have meant stripping His creation of its free will (Daniel 4:17; cf. Psalm 33:10–11). All His ways are good. In Him is “no darkness at all” (1 John 1:5), and He is right now working all things for His good pleasure (Romans 8:28; cf. Isaiah 46:9–10).
The mystery of evil and why God has allowed its reality with all of the suffering it causes may never be fully known in this world, but Scripture assures that evil is temporary. Once the culmination of God’s redemptive plan is complete, Jesus Christ will have destroyed the devil’s work forever (1 John 3:8).
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.