How did they become sanctified by God? Well I know you are probably going to disagree with me
but I think it has something to do with this:
Thus saith the LORD of hosts; I was jealous for Zion with great jealousy, and I was jealous for her with great fury.
(Zec 8:2)
Certainly a
MAJOR contributing factor to Israel's justification and sanctification is the LORD's jealously that He alone is worshiped by Y'isra'el.
Zechariah 8:23
Thus saith the LORD of hosts: In those days it shall come to pass, that ten men shall take hold, out of all the languages of the nations, shall even take hold of the skirt of him that is a Jew, saying: We will go with you, for we have heard that God is with you.
Ezekiel 37:22-23
22 And I will make them one nation in the land upon the mountains of Israel; and one king shall be king to them all: and they shall be no more two nations, neither shall they be divided into two kingdoms any more at all.
23 Neither shall they defile themselves any more with their idols, nor with their detestable things, nor with any of their transgressions: but I will save them out of all their dwelling places, wherein they have sinned, and will cleanse them: so shall they be my people, and I will be their God.
Jeremiah 31:31-34
31 Behold, the days come, said the LORD, in which I will make a new covenant with the house of Jacob and with the house of Judah:
32 not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt because they invalidated my covenant although I was a husband unto them, said the LORD;
33 But this is the covenant that I will make with the house of Israel after those days, said the LORD, I will give my law in their souls and write it in their hearts and will be their God, and they shall be my people.
34 And they shall no longer teach every man his neighbour and every man his brother, saying, Know the LORD, for they shall all know me, from the least of them unto the greatest of them, said the LORD, for I will forgive their iniquity, and I will remember their sin no more.
The above scriptures suggests that the time is coming wherein
God will both justify and sanctify Y'isra'el. True Worship of the LORD isn't possible without justification and sanctification ... so the LORD establishes a
new covenant (Jer. 31:33-34) ... because of His LOVE for Zion (Y'isra'el) ...
Zechariah 8:2
Thus saith the LORD of hosts; I was jealous for Zion with great jealousy, and I was jealous for her with great fury.