“Spiritual Israel”. The phrase is not found in scripture. A Spiritual Israel is never the recipient of promises or prophecy. God keeps His promises.
Daniel 2:44c "and the kingdom shall not be left to other people".
This is a part of why it is important to know who is really who in scripture and who is really who today.
John 10:16 "And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd."
This means that the other fold had to be physically descended from Jacob Israel. Hosea 1, Ephesians 2 and the parable of the Prodigal Son all verify this. This is why it is important to know about the two separate Houses of Israel. It is important to know how they became separated, how God viewed them and how they were prophesied to rejoin under one head, Christ, as they are today.
The idea of a Spiritual Israel was created by men who saw that those who are anti-Christ and claiming to be Israel were not fulfilling any prophecy for Israel. This was another instance of men trying to make sense of the Bible by changing the Bible. It is the world that is upside down, not the Kingdom of God. The method to understand the Bible is to change our understanding of the world. Those who hate Christ and spit when they hear His name are not God’s chosen. They do not hear His voice. They are not His sheep just like Christ said in John 5, 8 and 10. If you want to know who is Israel today, then look for the people who have followed and fulfilled prophecy for almost two thousand years.