This is the best answer I've read from "grace through faith"
According to Jeremiah 30:11 the purpose of the Great Tribulation is two-fold. One is to completely destroy the nations among which the Jews have been scattered, and the other is to discipline Israel. This discipline will cause them to recognize Jesus as their Messiah, and will happen in several stages.
The first is when as a nation they return to their Old Covenant relationship with God following the Battle of Ezekiel 38. (Ezekiel 39:22) prompting the building of a Temple in Israel. This is when Daniel’s 70th Week will begin. The second is when they petition God’s return to save them (Hosea 6:1-2), and the third is near the end of the Great Tribulation when they realize that Jesus has been their Messiah all along (Zechariah 12:10).
As I understand it the times of the Gentiles will be over. If they had there chance before the tribulation and didn't receive Christ it's to late. The tribulation is about the Jews only and has nothing to do with Gentiles as far as I know. This doesn't mean they can't be saved during the tribulation. it just that they will have no comforter or, Holy Spirit, for which to guide them only the scriptures and the two witnesses that has been prophesised.
Hope this helps.
MB
Matthew 24: 29 Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken:
30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
31 And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other.
Here we see that the church has been taken and following the Tribulation Christ has the elect (saved) gathered from the four winds in other words from all over the Earth.
This shows the ingathering at the End of the Tribualation. Matthew 24: 40 Then shall two be in the field; the one shall be taken, and the other left.
41 Two women shall be grinding at the mill; the one shall be taken, and the other left.
42 Watch therefore: for ye know not what hour your Lord doth come.
43 But know this, that if the goodman of the house had known in what watch the thief would come, he would have watched, and would not have suffered his house to be broken up.
44 Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh.
Again there are saved and unsaved together, from all nations. Appears there will. Couple that with Revelation 19:20 And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone.
21 And the remnant were slain with the sword of him that sat upon the horse, which sword proceeded out of his mouth: and all the fowls were filled with their flesh.
Revelation 20:4 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.
5 But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
Again appears that the saved who survive the Tribulation will be in the Messianic/Millineal Kingdom with Christ.
