What actually happens to those who do not accept Jesus as their Lord and Savior?

Question
What actually happens to those who do not accept Jesus as their Lord and Savior?
Response
For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved. He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. John 3:16–18
He who believes in the Son has everlasting life; and he who does not believe the Son shall not see life, but the wrath of God abides on him. John 3:36
And this is the testimony: that God has given us eternal life, and this life is in His Son. He who has the Son has life; he who does not have the Son of God does not have life. 1 John 5:11–12
In simplest terms, as these passages lay out, those who do not trust Jesus as Savior are condemned (v. 18) to perish (v. 16), under the wrath of God (v. 36), with no hope of eternal life (vv. 16, 18, 36). This will take place in what Jesus identified as hell (Mark 9:43–48; Luke 9:48, 16:19–31), and ultimately, at the Great White Throne Judgment, they will be thrown into the lake of fire.
Then I saw a great white throne and Him who sat on it, from whose face the earth and the heaven fled away, and there was found no place for them. And I saw the dead, small and great, standing before God, and books were opened. And another book was opened, which is the Book of Life. And the dead were judged according to their works, by the things which were written in the books. The sea gave up the dead who were in it, and Death and Hades delivered up the dead who were in them, and they were judged, each one according to his works. Then Death and Hades were cast into the lake of fire. This is the second death. And anyone not found written in the Book of Life was cast into the lake of fire.…But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death. Revelation 20:11–15, 21:8
Of all the topics found in the pages of Scripture, none is so loathsome and dreadful as the subject of hell, yet we dare not be blinded by ignorance, repulsion, or unbelief, for hell is a frightening reality that ought not be dismissed on the grounds of fear or unpleasantness. Despite the objections of some, the flames of hell will not be extinguished by clever Scripture-twisting or wishful thinking. The Bible has much to say about hell, and neither ignorance nor denial will cause this grim reality to go away.
We should understand the distinctions Scripture makes between “Sheol” and the “eternal lake of fire.” For purposes of this article, let’s speak of “hell” as commonly understood — a place of torment after death. The Bible says that the unrepentant (unbelievers) who die are immediately ushered into a dreadful holding place called “Hades.” In the following passage, Jesus details the horrid fate of an unregenerate sinner:
There was a rich man who was clothed in purple and fine linen and who feasted sumptuously every day. And at his gate was laid a poor man named Lazarus, covered with sores, who desired to be fed with what fell from the rich man’s table. Moreover, even the dogs came and licked his sores. The poor man died and was carried by the angels to Abraham’s side. The rich man also died and was buried, and in Hades, being in torment, he lifted up his eyes and saw Abraham far off and Lazarus at his side. And he called out, “Father Abraham, have mercy on me, and send Lazarus to dip the end of his finger in water and cool my tongue, for I am in anguish in this flame.” But Abraham said, “Child, remember that you in your lifetime received your good things, and Lazarus in like manner bad things; but now he is comforted here, and you are in anguish. And besides all this, between us and you a great chasm has been fixed, in order that those who would pass from here to you may not be able, and none may cross from there to us.” And he said, “Then I beg you, father, to send him to my father’s house—for I have five brothers—so that he may warn them, lest they also come into this place of torment.” But Abraham said, “They have Moses and the Prophets; let them hear them.” And he said, “No, father Abraham, but if someone goes to them from the dead, they will repent.” He said to him, “If they do not hear Moses and the Prophets, neither will they be convinced if someone should rise from the dead.” Luke 16:19–31
Hades (called “hell” in the KJV) is described as a place of “torment” and “anguish” (Luke 16:23–24). The rich man went there immediately upon his death. Scripture’s teaching is that all who die in their sins will immediately go to hell (Hades), where they will remain, conscious of their misery and despair, until summoned before God for judgment at the Great White Throne. These, who rejected God’s mercy, must face His wrath, and they are eventually cast into the lake of fire (Revelation 20:11–15).
The lake of fire, the place of eternal punishment, was never intended for man; God ordained the lake of fire as the final stop for Satan and his army of fallen angels (Matthew 25:41; 2 Peter 2:4; Revelation 20:10). Regrettably, legions of unrepentant people will, by their own volition, spend eternity with Satan and the demons who joined his unholy rebellion (Matthew 10:28; 25:46). Those who choose hell are rebels to the very end.
God does not delight in the suffering of unredeemed man. He takes no pleasure in the death of the wicked and would rather see them turn from their evil ways and live (Ezekiel 33:11). Hell is a necessary reality. Imagine a person who spent his or her entire life avoiding God. Regarding the Scriptures as fanciful myths, he or she had no use for Bible reading. He or she considered prayer a one-sided conversation with a nonexistent being. He or she maligned sincere Christian believers with unsavory labels and mocked their adherence to biblical morality. From reaching the age of accountability until his or her dying breath, he or she distanced him/herself from his/her Creator. How, then, could such a person be happy in heaven? How could he or she tolerate the presence of Jesus Christ and His followers throughout the endless ages to come? For such a person, heaven would be a hell. It is God’s will that none perish (2 Peter 3:9), but for those insistent rebels who reject His mercy, there is only justice. No third option exists.
A Small Glimpse into Eternity Without Christ
What does eternal separation from God look like? First, let’s establish that if we die in our sins, we are considered “the wicked”.
No Light
“God is Light, and in Him is no darkness at all.” 1 John 1:5
“He will guard the feet of His saints, but the wicked shall be silent in darkness.” 1 Samuel 2:9 (cf. Matthew 8:12; 25:30)
No Hope
Now hope does not disappoint, because the love of God has been poured out in our hearts by the Holy Spirit who was given to us. Romans 5:5
When a wicked man dies, his expectation will perish, and the hope of the unjust perishes. Proverbs 11:7
No Peace
Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ. Romans 5:1
“There is no peace,” says my God, “for the wicked.” Isaiah 57:21
No Refuge
Trust in Him at all times, you people; pour out your heart before Him; God is a refuge for us. Selah. Psalm 62:8
The wicked is banished in his wickedness, but the righteous has a refuge in his death. Proverbs 14:32
None of His Goodness… All of His Anger
Surely goodness and mercy shall follow me all the days of my life; And I will dwell in the house of the Lord Forever. Psalm 23:6
God is a just judge, And God is angry with the wicked every day. Psalm 7:11
The sacrifice of the wicked is an abomination to the Lord, but the prayer of the upright is His delight. Proverbs 15:8
The Lord is far from the wicked, but He hears the prayer of the righteous. Proverbs 15:29
And There Will Be Torment
Upon the wicked He will rain coals; fire and brimstone and a burning wind shall be the portion of their cup. Psalm 11:6
But the wicked shall perish;
And the enemies of the Lord,
Like the splendor of the meadows, shall vanish.
Into smoke they shall vanish away. Psalm 37:20
This is not an exhaustive list, by any means.
Why Such Judgment?
Let’s first clear up a small misconception that many of us have been taught all of our lives:
We are all created in the image of God and worthy of dignity due to that fact alone (Psalm 139). We are not, however, all children of God. That privilege belongs only to those who receive Jesus as Messiah — that is, who believe that His death satisfied our sin debt and His resurrection guarantees us eternal life and a relationship with God.
But as many as received Him, to them He gave the right to become children of God, to those who believe in His name: who were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God. John 1:12–13
No, we…
…were dead in trespasses and sins, in which you once walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the sons of disobedience, among whom also we all once conducted ourselves in the lusts of our flesh, fulfilling the desires of the flesh and of the mind, and were by nature children of wrath, just as the others. Ephesians 2:1–3
and rebels against the Holy, Righteous Sovereign of the Universe (Romans 5:9–11).
God’s holiness lays our sin bare before Him (Romans 3:10), and we will always fall short of His standard, which is His perfect holiness (Romans 3:23). Our best efforts to be right before Him are worthless (Isaiah 64:6). The judgment our sins have earned us:
1. Eternal Separation from God
The wages (earned payment) of sin is death, but the gift of God is eternal life through Jesus Christ our Lord. Romans 6:23
2. The Wrath of the Holy, Righteous God
For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness, because what may be known of God is manifest in them, for God has shown it to them. Romans 1:18–19
But the Love of God Made a Way
For when we were still without strength, in due time Christ died for the ungodly. For scarcely for a righteous man will one die; yet perhaps for a good man someone would even dare to die. But God demonstrates His own love toward us, in that while we were still sinners, Christ died for us. Much more then, having now been justified by His blood, we shall be saved from wrath through Him. For if when we were enemies we were reconciled to God through the death of His Son, much more, having been reconciled, we shall be saved by His life. Romans 5:6–10
And He Made It Exclusive to Him Alone
I am the Way, the Truth and the Life, no one comes to the Father, except through Me. John 14:6
Let it be known to you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, whom you crucified, whom God raised from the dead, by Him this man stands here before you whole. This is the stone which was rejected by you builders, which has become the chief cornerstone. Nor is there salvation in any other, for there is no other name under heaven given among men by which we must be saved. Acts 4:10–12
This small look into a Christless eternity is also a glimpse into the cup (Luke 22:39–46) that Jesus drank on the cross when He took our place.
For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him. 2 Corinthians 5:21
When Jesus became sin for us, He took the wrath of God that our sins deserved (Isaiah 53:4–6). On the cross, the judgment the wicked deserve was put on Him.
Upon death, the lost are immediately sent to the place of their choosing, Hades (hell), where they will remain until the judgment convened at the close of our Lord’s millennial kingdom. At that time, they will be consigned to the lake of fire along with Satan and his demonic forces. Forever, they will remain fixed in this diabolical state of being.
To think anyone would choose never-ending misery over God’s everlasting joy is unfathomable, yet it is true.
How shall we escape if we neglect so great a salvation (Hebrews 2:3)…
The answer is, we don’t…
For if we sin willfully after we have received the knowledge of the truth, there no longer remains a sacrifice for sins, but a certain fearful expectation of judgment, and fiery indignation which will devour the adversaries. Anyone who has rejected Moses’ law dies without mercy on the testimony of two or three witnesses. Of how much worse punishment, do you suppose, will he be thought worthy who has trampled the Son of God underfoot, counted the blood of the covenant by which he was sanctified a common thing, and insulted the Spirit of grace… It is a fearful thing to fall into the hands of the living God. Hebrews 10:26–29, 31