There are other things on either side of the dividing line besides Israel and her blessings on one hand, and the nations with their blessings on the other. for on the other side of that line lies the whole Old Testament, including all the books written during Acts. So the farthest you can go back is to Adam and Eve and the law given to them, if we can call it that. At least it contained the phrase, Thou shalt not. See Gen. 2:17 and 3:3.
Also on the far side of this line is the history of the nations and their fall, the call of Abraham and the institution of a nation which should be a priestly nation to the nations then given up (Rom. 1:18-32). There are warnings all through of what would happen if Israel did not follow the law and worship Jehovah. Of course it did happen, and so we have that dividing line.
Israel had both Priest and King in the person of Christ. We have this mentioned in Heb. 6:20 and 7:1, it tells us that this Melchisedec was king of Salem (later Jerusalem) and also a priest. No doubt this man was Shem. But being before the tribes of Israel, he could hold both offices, and that without father or mother, in other words he did not inherit these titles. And so it was with the Lord. He is the King of Israel from the tribe of Judah, and that is inherited, but also He is a priest not of the tribe of Levi, but after the order of Melchisedec. I hope that this is plain.
But on this side of the line He is King in the heavenly places, but not in relation to the earth. And above all, He now is Head of the church which is His body, and that is both in heaven and earth as indicated in Eph. 1:9,10. Note Colossians. 1:13, "Who hath delivered (rescued) us from the power of darkness, and hath translated us into the kingdom of His dear Son." Now this is a universal rule and not just His being King of Israel here on the earth. We mention this because so many try to build a doctrine on a word. But that word must be examined.
Now, summing up these important items, we must mention that Christ is the Creator of the nations, the Jehovah or King of Israel, and Head of the church which is His body which is joined with the principalities and powers in the heavenly places. Search and see.
But one of the greatest differences between the two sides of the line might be worship. From the very beginning worship consisted in things done by the hands of the worshipers. An altar and a sacrifice were the foundation. And added to that was a place of worship. Later on were the priests and other persons connected with the worship.
A little prophetic note is found in John 4:23. It is foreshadowing of worship as it should be now. It was to be in spirit and in truth. And so we find it taught by Paul in Philippians 3:3, worship in spirit without works (flesh excluded).