Another reason why we cannot make Israel and the Church the same Body is that we would have to say that only those of Israel were "saved" prior to Pentecost.
Ephesians 2:12-15
King James Version (KJV)
12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
14 For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us;
15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
Now does Paul speak about the "Spiritual Israel" here? Is that what is in view?
Or National Israel?
The Spiritual Israel most try to correlate to an Old Testament Church did not exclude Gentiles, and this for one simple reason: many of the Household of Faith were not of Israel.
This would include Abel, Noah, Abraham, et cetera.
God bless.