Where does it say in the bible Israel will never be destroyed?

The real key is to scripturally determine who/what is actually Israel. Originally, Jacob wrestled with God and received the name of "Israel", along with a limp and a new perspective, through which he was able to see God in the face of his enemies.

Only those loyal to Christ, the King of Israel, are legal Israelites. The nation currently calling itself "Israel" is a faction of usurpers attempting to take the kingdom by force and deception. Jesus says we'll know them by their fruit, so we might want to assess whether we've seen this faux-Israel even attempt to meet the directives given them in the Sermon on the Mount. 64 years is a pretty long window.

It also says that the TRUE ISRAEL OF GOD is composed of BOTH Jews and Gentiles, and is NOT a people-group on Earth, but a SPIRITUAL group of people. The nation of Israel is NOT the TRUE ISRAEL OF GOD!

You have it wrong mate, the bible is clear that Israel will become a nation again, And will also become a stumbling block for the nations(will be a major problem) They will have no King and no sacrifice. Do you not have any access to the news of what is going on in the world? 2 thirds of them(modern day Israel) will die the rest will see Jesus coming in the clouds and will mourn for him whom they have pierced. As for the current Israeli government? they will go the same way as all earthly man ruled governments.

Where does it say that? Quote please.

My Father, whom you (Jews) claim as your God, is the one who glorifies me. Though you do not know him, I know him. If I said I did not, I would be a liar like you, but I do know him and keep his word. John 8:55

John 4:22,23 You (non-Jews) worship you know not what: we know what we worship: for salvation is of the Jews.

But the hour cometh, and now is, when the true worshippers shall worship the Father in spirit and in truth: for the Father seeketh such to worship him.

... flesh and blood cannot inherit the kingdom of God, nor does the perishable inherit the imperishable. 1 Corinthians 15:50

Can someone break it down a little bit?

So it doesn't actually say "the TRUE ISRAEL OF GOD is composed of BOTH Jews and Gentiles"?

Can someone break it down a little bit?

Lol, gentile thread. A lot of you are going to be VERY disappointed when you come to realize the Israel spoken of in the bible is not the group of people claiming that Royal identity today.

Do your own research you lazy arsehole.