After all believers in Christ are raptured away to heaven, the people who come to faith in Christ will become what is commonly called tribulation saints. The Bible predicts that a huge number of people will be saved during the tribulation hour. Rev 7:9 describes the number as a "great multitude, which no man could number."
The Bible repeatedly states that tribulation saints will face a strong likelihood of being martyred under the Antichrist's demonic rule. The reason why they are called tribulation saints is because most of them will have to pay the ultimate price for their faith. There are several passages that warn how rough it will be for Christians to endure the tribulation:
"And it was given unto him to make war with the saints, and to overcome them: and power was given him over all kindreds, and tongues, and nations" (Rev 13:7).
"He that leadeth into captivity shall go into captivity: he that killeth with the sword must be killed with the sword. Here is the patience and the faith of the saints" (Rev 13:10).
"And he had power to give life unto the image of the beast, that the image of the beast should both speak, and cause that as many as would not worship the image of the beast should be killed" (Rev 13:15).
"Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus. And I heard a voice from heaven saying unto me, Write, Blessed are the dead which die in the Lord from henceforth: Yea, saith the Spirit, that they may rest from their labors; and their works do follow them" (Rev 14:12-13).
"And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years" (Rev 20:4).
The tribulation saints will not be silent during these dark years, nor will they roll over and play dead for Antichrist. These Christians will continue serving their Lord Jesus Christ in the midst of their desperate surroundings. Faithful to the end, some of these Christians will die for their beliefs, but God shall reward them in this manner: "Therefore they are before the throne of God, and serve Him day and night in His temple. And He who sits on the throne will dwell among them. They shall neither hunger anymore nor thirst anymore; the sun shall not strike them, nor any heat; for the Lamb who is in the midst of the throne will shepherd them and lead them to living fountains of waters. And God will wipe away every tear from their eyes (Revelation 7: 15-17 NKJV)." (1)
A realization of how difficult it will be for tribulation saints has motivated many christian to leave helpful advice for those left behind. Here are two examples from RR and another site:
First of all, it is to warn those who receive this manual prior to the rapture of the events that will take place in the last days as foretold in the Bible. Based on what the Bible has to say about future events, nobody in their right mind would want live on earth after the rapture. Hopefully, many will read, believe, seek God, repent and be saved. Salvation is very simple, so simple to attain, in fact, that most people cannot accept its simplicity; thereby reject it completely. However, it is complex because it is life-changing and based on that which we cannot see; it is based on faith. Simple, because Jesus does all the work. If you want to be saved and have eternal life, simply pray in belief and humility to the Lord Jesus:
"Lord Jesus, I know that I am a sinner and ask you to forgive me of my sins and prepare for me a new heart. I surrender my life to you."
Your predicament is quite serious, so this is very important: Try to find a Holy Bible (containing 66 books), which you must study and know well ---although that task will present some very thorny problems--- because if you are reading this at the beginning of the tribulation, then all of you "tribulation saints" are brand new "baby" believers in Christ. There are no older believers to help you in person, so, you'll have to survive on your own, without such a support group ...there is no true "Church" on earth... that's why I'm concerned to write to you. (2)