When did Satan fall from heaven? What was the reason?
Satan and Mankind’s Fall
Pride was the main cause for both Satan’s (Lucifer at the time) and mankind’s fall. For that matter, pride seems to be at the center of all sin. After the fall, which we will read about in the next paragraph, Satan was probably jealous that mankind was given dominion over the earth as Genesis 1:26 says “let them have dominion over the fish of the sea and over the birds of the heavens and over the livestock and over all the earth and over every creeping thing that creeps on the earth.” Satan hatched a plan. He would deceive Eve and make her disobey God by taking to eat of the tree of the knowledge of good and evil and Adam would do the same. After this, “And the LORD God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live forever” (Gen 3:22) and so “the LORD God banished him from the Garden of Eden to work the ground from which he had been taken” (Gen 3:23). Not only were they banished from the Garden of Eden, they would now receive their wages and that was death (Rom 6:23) and would eventually die because the soul that sins will die (Ezk 18:20). They had lost their chance at eternal life and their only hope would be that they repented but there is no evidence that they ever did. We just don’t know for sure if they ever did.
The Fall of Satan
Isaiah gives us a good look at the cause of Lucifer’s fall from heaven in Isaiah 14:12 “How you have fallen from heaven, O star of the morning, son of the dawn! You have been cut down to the earth, You who have weakened the nations”. The Hebrew word for “star” is “Helel” or “Hylel” and means the “shining one” so Lucifer must have been a glorious angel full of light at one time but then something drastic happened, “But you said in your heart, ‘I will ascend to heaven; I will raise my throne above the stars of God, And I will sit on the mount of assembly In the recesses of the north” (Isaiah 14:13). Here we read that Lucifer was full of himself, full of pride , and wanted to “ascend to heaven” and raise his throne about the stars (or angels) of God and wanted to “sit on the mount of assembly in the recesses of the north” meaning he wanted to sit on the throne of God but in place of God. This fall must have apparently happened shortly after the earth was created for he had to have had an earth to be cast down too.
Lucifer wasn’t satisfied with his state…he wanted more which is why it was written “I will ascend above the heights of the clouds; I will make myself like the Most High” (Isaiah 14:14). In other words, Lucifer (or Satan) wanted to “ascend above the heights of the clouds” of which the clouds represent God’s Shekinah glory and he wanted that glory. Even more, he lusted in his prideful heart saying “I make myself like the Most High” God and he wanted to be God because he desired worship. He still desires that today but the bad news for him is he “will be thrust down to Sheol, to the recesses of the pit” (Isaiah 14:15) and the final consummation of that is described in Revelation 20:10 “And the devil who deceived them was thrown into the lake of fire and brimstone, where the beast and the false prophet are also; and they will be tormented day and night forever and ever.”
Pride Before the Fall
Satan wasn’t the only one to fall and there will yet be more in the future. That’s because anyone who is full of pride is at war with God (James 4:6) because “Pride brings a person low, but the lowly in spirit gain honor” (Prov 29:23) which is why James wrote “Humble yourselves before the Lord, and he will lift you up” (James 4:10). The opposite of that is true as well; if you lift yourself up, He will humble you. Either we will humble ourselves before God or He will do it for us and guess which one is more painful? This is because “God opposes the proud but shows favor to the humble” (1 Pet 5:5). For those who refuse to voluntarily humble themselves God warns “Pride goes before destruction, and a haughty spirit before a fall” (Prov 16:18). The word “haughty” means lifted up or to look down upon others from a lofty position and that position is only for God to have. To be haughty is to be full of pride and God will not tolerate such an attitude, just as He didn’t tolerate Lucifer’s pride.
The Self-Absorbed Lucifer
Ezekiel wrote about the prior state of Lucifer by writing “You had the seal of perfection, Full of wisdom and perfect in beauty” (Ezk 28:11). At one time he was “the anointed cherub who covers, and I placed you there. You were on the holy mountain of God; you walked in the midst of the stones of fire” (Ezk 28:14) and “You were blameless in your ways from the day you were created until unrighteousness was found in you” (Ezk 28:15). God describes the reason for Lucifer (or Satan’s) fall “Your heart was lifted up because of your beauty; you corrupted your wisdom by reason of your splendor. I cast you to the ground” (Ezk 28:17). He was in love…with himself and so his “heart was lifted up” because of pride due to his beauty, wisdom, and splendor. There are many in the unsaved world today just like that and their fate will be the very same fate as Satan’s spoken of in Revelation 20:10-15.
Why more of us, including myself, won’t humble ourselves is a mystery to me. If we only fully understood the awesome, majestic, glory of God, we would all fall down before Him and humble ourselves . No one can truly be saved until they humble themselves before God, until they repent of their sins, meaning that they turn away from them and forsake them and then turn to their only hope of being saved and that is Jesus Christ. He will be your Lord and Savior or He will be your Judge. That decision is strictly up to you.
More about Lucifer (Satan) here: Is There Really a Being Called Satan? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), copyright © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.