“The Lord knows how to deliver the godly out of temptations and to reserve the unjust
under punishment for the day of judgment” (2 Peter 2:9).
There is not one single soul in hellfire today. The Bible says that God reserves, or holds back, the wicked until the day of judgment to be punished.
“So it will be at the end of this age. The Son of Man will send out His angels, and they will gather out of His kingdom all things that offend, and those who practice lawlessness, and will cast them into the furnace of fire” (Matthew 13:40–42).
The scripture above is in reference to when the Lord returns to the earth to end the age. When He sends out His angels, they will be gathering the wicked who made it alive through the entire tribulation period. When they are killed, their spirits will also go into Hades and remain there until the great white throne judgment. Matthew 13:40-42 has nothing to do with those who are in Hades.
“The word that I have spoken will judge him in the last day” (John 12:48).
The lost will be cast into hellfire at the great judgment at the end of the world—not when they die. God would not punish a person in fire until his or her case was tried and decided in court at the end of the world. Does it make sense that God would burn a murderer who died 5,000 years ago 5,000 years longer than a murderer who dies today and deserves the same punishment for the same sin?"
You are correct in that, the unsaved will be cast into the lake of fire at the great white throne judgment, but that does not do away with the fact that they will have already been suffering punishment in Hades.
God already knows those who belong to Him and who is destined for eternal punishment. The great white throne judgment will be the formal, legal process of sentencing those who died in their sins to the lake of fire. The great white throne judgment which takes place after the millennial kingdom, is the final or official judgment for sentencing.
scripture states that when the unsaved die, their spirits descend into Hades, which is what the event of the rich man and Lazarus of Luke 16:19-31 supports. In addition, Revelation 20:11-15, which is a glimpse of the great white throne judgment, has the spirits of the unrighteous dead being released from Hades to be judged. Therefore, there are many spirits currently in Hades and it continues to receive the spirits of the unsaved 24/7.
"The sea gave up its dead, and Death
and Hades gave up their dead, and each one was judged according to his deeds."
"And the rich man also died and was buried.
In Hades, where he was in torment, he looked up and saw Abraham from afar, with Lazarus by his side."
Hades is the same place that the spirit of the rich man went to and who is still there. At the end of the millennial kingdom, just as the scripture above states, the spirits of those who will have been in torment in Hades will be released to stand before God for their official, legal trial.
Those who interpret the event of the rich man and Lazarus as being a parable, distort the literal meanings contained in the context. In essence, by calling it a parable they get rid of it as a proof and then ask for more proof. Make no mistake, when the unsaved die, they immediately begin their punishment in Hades.
For the believer, at the time of death, their spirit departs and goes to be in the presence of the Lord (2 Cor.5:6-9, Phil.1:21-23). For those who die without Christ, like the rich man, their spirit departs and goes down into Hades to begin their punishment. The great white throne will just be the legal process of sentencing which will result in eternal separation from God in the lake of fire.