What exactly do you mean by "Israel is not Spirit"? The Church is believing Jews and Gentiles in one Body (without distinctions) until the Resurrection/Rapture, when the fulness of the Gentiles will be completed.
Following that God will resume His dealings with Israel directly through Christ. Study Romans 11 carefully in conjunction with all the prophecies concerning redeemed and restored Israel on earth.
As to the importance of keeping Israel separate, God has an important and vital role for Israel on earth for eternity, and its influence on all the saved nations of the earth.
It was a question...is Israel not Spirit. We both agree yes, correct? Are there two Spirits then? Cause when the word says we come to not a mountain burning that can’t be approached but to a heavenly host of men made perfect that includes Abraham, Issac, and Jacob. If we are Spirit...we are born of the same Spirit and promise. Same promise made to Abraham. The only reason for saying the Spirit of God is divided (Israel and church) is: how do our endtime views hold up to God of Abraham and Israel are Spirit and the same Spirit we are born of. Not a Spirit divided...but a family. Fellowship. Made whole. Not in halves.
Daniel 8:13-14
[13] Then I heard one saint speaking, and another saint said unto that certain saint which spake, How long shall be the vision concerning the daily sacrifice , and the transgression of desolation, to give both the sanctuary and the host to be trodden under foot? [14] And he said unto me, Unto two thousand and three hundred days; then shall the sanctuary be cleansed.
What sanctuary shall be cleansed??
Matthew 27:40-43
[40] And saying, Thou that destroyest the temple, and buildest it in three days, save thyself. If thou be the Son of God, come down from the cross. [41] Likewise also the chief priests mocking him , with the scribes and elders, said, [42] He saved others; himself he cannot save. If he be the King of Israel, let him now come down from the cross, and we will believe him. [43] He trusted in God; let him deliver him now, if he will have him: for he said, I am the Son of God.
Ecclesiastes 3:1-8
[1] To every thing there is a season, and a time to every purpose under the heaven: A time to be born, and a time to die;
a time to plant, and a time to pluck up that which is planted;
A time to kill, and a time to heal;
a time to break down, and a time to build up;
A time to weep, and a time to laugh;
a time to mourn, and a time to dance;
A time to
cast away stones, and a time to
gather stones together;
a time to embrace, and a time to refrain from embracing;
A time to get, and a time to lose;
a time to keep, and a time to cast away;
A time to rend, and a time to sew;
a time to keep silence, and a time to speak;
A time to love, and a time to hate;
a time of war, and a time of peace.
1 Peter 2:5 KJV
[5] Ye also, as lively stones, are built up a spiritual house, an holy priesthood, to offer up spiritual sacrifices, acceptable to God by Jesus Christ.
Israel ...Spirit.
Which we are born of.