Church & Israel

Seems pretty clear to me:

Those who have faith in Christ are the children of Abraham (i.e. Israel) (Gal 3.7)

If you belong to Christ, then you are Abraham's seed (Gal 3.29)

The present Jerusalem is in slavery, but the Jerusalem above is free, and she is our mother (Gal 4.26)

Like Isaac, we (believers) are children of promise (Gal 4.28)

We are not children of the slave woman - Hagar who represents Sinai, but of the free woman (Gal 4.31)

Those who walk in line with the rule that circumcision or uncircumcisioin means nothing but the new creation means everything (i.e. Christians) are the Israel of God (Gal 6.15-16)

A Jew is one inwardly, not outwardly and circumcision is of the heart, by the Spirit, not the letter (Rom 2.28-29)

We (Christians) are the circumcision (i.e. Israel), who serve God by the Spirit, who glory in Christ Jesus, and put no confidence in the flesh (Phil 3.2-3)