Elijah the prophet, in the days of Ahab the king and Jezebel, cried out to God:I have been very zealous for the Lord God Almighty. The Israelites have rejected your covenant, broken down your altars, and put your prophets to death with the sword. I am the only one left and now they are trying to kill me too." 1 Kings 19:10
Elijah, the prophet, thought that he was the only faithful Israelite left, but God responded to him: Yet I reserve seven thousand in Israel--all whose knees have not bowed down to Baal and all whose mouths have not kissed him." 1 Kings 19:18
Paul, in Romans chapter eleven, quotes these two passages, and then assures us that at this present time God still has a remnant of Israelites that have always remained faithful to him, even though they are not Christians.
Romans 11:5
"So too, at the present time there is a remnant chosen by grace."
1 Corinthians 1:22-24
Jews demand miraculous signs and Greeks look for wisdom, 23 but we preach Christ crucified: a stumbling block to Jews and foolishness to Gentiles, 24 but to those whom God has called, both Jews and Greeks, Christ the power of God and the wisdom of God.(NIV)
Notice that there are three categories of people in this passage. 1) Jews. 2) Greeks, or Gentiles. 3) We, (Christians). It is important to understand that this is true. The woman in Revelation chapter twelve is the faithful remnant of the children of Israel. Before the Lord's return she still does not accept that Jesus is her Messiah and so she is left behind at the "catching-up" of the Church, (commonly called the rapture), but she has been faithful to God's Spirit of truth and goodness and blamelessness. Immediately after the Church is taken from the earth she then believes that Jesus is in fact her Messiah.
Romans 11:25-32
I do not want you to be ignorant of this mystery, brothers, so that you may not be conceited: Israel has experienced a hardening in part until the full number of the Gentiles has come in. 26 And so all Israel will be saved, as it is written:
"The deliverer will come from Zion;
he will turn godlessness away from Jacob.
27 And this is my covenant with them
when I take away their sins."
28 As far as the gospel is concerned, they are enemies on your account; but as far as election is concerned, they are loved on account of the patriarchs, 29 for God's gifts and his call are irrevocable. 30 Just as you who were at one time disobedient to God have now received mercy as a result of their disobedience, 31 so they too have now become disobedient in order that they too may now receive mercy as a result of God's mercy to you. 32 For God has bound all men over to disobedience so that he may have mercy on them all. (NIV)
In this passage we see that as the full number of Gentiles comes into the Church--then the Church rises up into the clouds to meet the Lord in the air--then the remnant believes unto salvation.
It is important that we make the distinction that she is the blameless remnant of Israel and not just the descendants of Israel. She is pure and holy and God has marked her with his seal, so that Satan can't touch her during the time of testing. Her other descendants are the descendants of Israel that acknowledge God, but not whole heartedly. They will be subject to the actions of the Beast in order to move them to repentance, and to teach them to rely upon the Lord.
This is the same today, by brothers and sisters, if you will give yourselves over to the Lord, one hundred percent, God will prevent Satan from touching you in any way. The trials and tests that we do experience are given to encourage us to repent of worldly ways, and live fully for the Lord.
The time that the woman flees into the desert can be determined by counting back from the time that the Beast who desires to kill her is himself destroyed. If we start at his death and count backwards the time she was to flee we find that she started her hiding 3 1/2 years before the end of the time of testing. Which is at the time of the abomination that causes desolation sign spoken of in Daniel 9:27, Matthew 24:15, and 2 Thessalonians 2:4.