Let's assume pre-trib rapture for the sake of conversation (I don't agree with it, but we can still explore the idea). Would this be any different than hell (Hades)?
Is it possible to attain salvation when in hell
NO, it is not possible to be saved after the death of the body! Today is the day of salvation i.e. while one is still alive to have faith. After the death of the body our records are sealed and there is no offer of salvation. This truth is demonstrated in the event of the rich man and Lazarus. Both Lazarus and the rich man had died, but their spirits were in Hades separated by a great chasm. Abraham and Lazarus were on the side of comfort. While the rich man was on the side of torment in flame. The rich man asked Abraham to send Lazarus back up from the dead to his father's house so that he could warn his five brothers so that they would not come to that place of torment in flame. But the answer was that they had Moses and the prophets (word of God) to warn them. Once one dies, one would know the truth and there would be no need for faith. For faith is the the things hoped for but not yet seen. Who would not take the offer of salvation if they were suffering in torment in flame? Hades would be empty in that case and no one would be cast into the lake of fire at the great white throne judgement.
When a believer in Christ dies, their spirit departs and goes to be in the presence of Christ (2 Cor.5:6-8, Phil.1:21-26)
When an unbelieve dies, their spirits depart and go down into Hades to begin their punishment, just as the rich man did.
or when we are left behind in the rapture?
In Revelation 7:9-17, we are introduced to a group which no man can count from every nation, people, tribe and language (Gentiles) who will become believers and take their stand for Christ even in the face of extreme persecution and death and who will not worship the beast, his image nor receive his mark. These are those saints who come out of the great tribulation period. In answer to your question, I'm sure that there will be many who believed in Christ who will have gone back into the world, and once again will be living according to the sinful nature, not keeping watch. When the church is gathered, they will know what has happened and will grieve because of their error. Many of these I'm sure will be apart of that group previously mentioned, as they know that it will be their only hope of salvation, since they were not ready when the Lord came to gather His church. The Lord warns believers about this very situation, demonstrated in the scripture below:
“Be careful, or your hearts will be weighed down with carousing, drunkenness and the anxieties of life, and that day will close on you suddenly like a trap. For it will come on all those who live on the face of the whole earth. Be always on the watch, and pray that you may be able to escape all that is about to happen, and that you may be able to stand before the Son of Man.” - Luke 21:37-36
Is there anything that definitively says yay or nay for pre-trib rapture?
This basic principle that Christ took upon himself God's wrath on behalf of every believer, satisfying it completely is one that many overlook. Since this is true, God's wrath no longer rests upon the believer. When we believed we were credited with the righteousness of Christ and reconciled to God. It is because of this that the scripture says that "we are not appointed to suffer God's wrath."
"Since we have now been justified by his blood, how much more shall we be saved from God’s wrath through him!"
"They tell how you turned to God from idols to serve the living and true God, and to wait for his Son from heaven, whom he raised from the dead—Jesus, who rescues us from the coming wrath. - 1 Thess.1:9-10
"But since we belong to the day, let us be sober, putting on faith and love as a breastplate, and the hope of salvation as a helmet. For God did not appoint us to suffer wrath but to receive salvation through our Lord Jesus Christ. - 1 Thess.5:9
"Because you have kept the word of My patient endurance, I also will
keep you out of the hour of the trial being about to come upon the whole inhabited world, to try those dwelling upon the earth." - Rev.3:10
The 'hour of trial' is another title describing the Day of the Lord, the time of God's wrath, which is about to come upon the whole world and which is what the majority of the book of Revelation is revealing. The word 'ek' above is translated as 'out of' which means that believers will be kept out of that time of God's wrath, which will take place when the Lord comes to gather His church, which has always been imminent.
Another reason that current believers in Christ cannot be on the earth during the time of God's wrath, is because God does not punish the righteous with the wicked. Jesus said that those who believe in Him would have trials and persecutions because of our faith in Him and which come at the hands of men and the powers of darkness. God's coming wrath is not the same as these common trials, but will be God's direct wrath being poured out on a Christ rejecting world and the fulfillment of His dealing with Israel to finish transgression, to put an end to sin, to atone for wickedness, to bring in everlasting righteousness, to seal up vision and prophecy and to anoint the Most Holy Place. - Daniel 9:24
"Surely He took on our infirmities and carried our sorrows; yet we considered Him stricken by God, struck down and afflicted. But He was pierced for our transgressions, He was crushed for our iniquities;
the punishment that brought us peace was upon Him, and by His stripes we are healed. - Isaiah 53:4-5
I hope that you agree with it now. Otherwise, you are not truly believing that Christ satisfied God's wrath on our behalf.
