Replies

No one can say they believe that Jesus is Lord, the Son of God except by the power of the Holy Spirit that dwells within you. What would God send with them unless they go out with the power of the Holy Spirit and since, according to the Rapture theory, the church is removed and along with the church, the Holy Spirit. He’s gone.

I will disagree gently on this point.
The Holy Spirit came to permanently indwell believers at Pentecost.
Before then, the Spirit came upon Jews temporarily, for extraordinary service and enablement.
The removal of the Church at the rapture removes the indwelling Spirit, but of course God Himself is present everywhere, including the earth.
It seems that what is causing difficulty in this discussion is *who* comes to faith during the tribulation and *how*
Some Jews and gentiles who are not killed in the tribulation outpourings will become believers. They will not become part of the church, which will be complete before the rapture - and as the Bride of Christ, before the wedding in Revelation 19. Some who believe in God and are killed are present at the wedding - as guests, but not as part of the Bride.
How do people become believers without the Holy Spirit indwelling other people on earth at that time?
This happens exactly the same way as it did before Christ came. It has always been salvation by faith.
"Abram believed the LORD, and he credited it to him as righteousness."
Abram is not part of the Body and Bride of Christ. He is however, a believer.
God's 144,000 Jewish witnesses (Revelation 7:4), selected from the 12 tribes of Israel, will go forth proclaiming Christ as Messiah. These 144,000 men are sealed by God and are commissioned to go and call the Jews from the four corners of the world to repentance.
I feel quite safe in assuming that they will be given everything needed for their unique ministry during the great tribulation.
I assume you do not doubt God will equip those whom He calls?
These 144,000 Jews are “sealed,” which means they have the special protection of God. They are kept safe from the divine judgments and from the wrath of the Antichrist.