Explain why the Church is not considered the “Israel of God?” BIB 536 - Session 08-6

Before studying the Book of Galatians I would’ve been quick to answer this discussion question by pointing out the unconditional and eternal covenant that God has with Abraham that was passed down to his son and grandson. A question dealing with God’s covenant with Abraham, etc., would have been far easier to answer then the current question, so on with the challenge of a new understanding.
Paul introduced me to the concept of the “Israel of God.” Paul classifies physical Israel as including all Jews. However, spiritual Israel includes those Jews who are believers. In this respect circumcision or non-circumstance has no real relevancy. When speaking of “the circumcised” it was a mind set, an equivalency to those who live by the Mosaic laws rather than the removal of a little piece of skin. Those known as “the circumcised” were adding works to grace and/or being trapped in legalese.
Paul also spoke of circumcision either of the heart (spiritual) or of the flesh (outwardly). Romans 2:27-29 “And shall not uncircumcision which is by nature, if it fulfil the law, judge thee, who by the letter and circumcision dost transgress the law? For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.” Circumcision of the flesh sounds like it was being done out of pride rather than devotion.
As for the church, rather than being considered as the “Israel of God,” we are Gentiles who are in Christ but not a replacement of Israel. This would border on replacement theology which has been responsible for unspeakable evil and genocide.
We in the Church can take comfort in Colossians 3:11 “Where there is neither Greek nor Jew, circumcision nor uncircumcision, Barbarian, Scythian, bond nor free: but Christ is all, and in all.” And 2 Corinthians 5:!7 “Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new” Plus Galatians 5:6 “For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love.”