Romans 9:6-8
6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
7 Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.
8 That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.
Galatians 3:28-29
28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
It doesn't expressly say "Spiritual Israel" but I think the concept of Spiritual Israel is plainly stated.
6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
7 Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.
8 That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.
Galatians 3:28-29
28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
It doesn't expressly say "Spiritual Israel" but I think the concept of Spiritual Israel is plainly stated.
Galatians is simply stating that we, as believing Gentiles, are children of the promise...
Genesis 17:4 NKJV
[4] "As for Me, behold, My covenant is with you, and you shall be a father of many nations.
Romans 4:17 NKJV
[17] (as it is written, "I have made you a father of many nations") in the presence of Him whom he believed-God, who gives life to the dead and calls those things which do not exist as though they did;