What I think says all I'm able to further say on this topic, Galatians 4:8-11 in Context:
“Though but a man’s will yet confirmed, it is impossible to annul, or to be added to.” (3:15) How much surer therefore, if God’s ‘Will’!
God ensured His will – in Paul’s own words – that “the blessing of Abraham might come on the Gentiles”. In the Old Testament – in “the Scripture”, says Paul in verse 8, “it says, In you (Abraham), will all the nations be blessed” – plural, many, “all” the nations, the Gentiles included!
Paul wonders, ‘How on earth – the blessing of “our father Abraham” … on the Gentiles?! How impossible, they are not “sons”? They are not the “heirs” by right – ‘by Law’? Not those ‘dogs’! Isn’t this going to be grossly unfair of God that the “children of Abraham” – Israel – are passed by, while the Gentiles, the “cursed” – “for it is written, Cursed is everyone that continueth NOT in all the things which are written in the book of the Law, to do them” – that they, receive the promise and the blessing of Abraham, our – the Jews – father? These Gentiles, they don’t keep the Law! We, the Jews, we, greatly respect God’s holy Law. We, every day do our very best to obey every letter of God’s Commandments and Ordinances. SHOULD NOT the promises of God come OUR way? Isn’t it just fair, fair to us, who are the “children of Abraham” by promise and testament; fair to the Law that says the “heir” shall receive the blessing? Are not WE, “the heir”? How can “the blessing of Abraham”, “come on the Gentiles”, those disobedient and “cursed” “strangers to the promises of God”?.
Here is Paul’s solution:
“Now to Abraham (first), and his seed (after), were the promises made” – not, to the Jews first, then, to the Gentiles!
To Abraham, first! How obtained Abraham the promises of God? “As Abraham believed God, it was accounted to him for righteousness.” Abraham, like the Gentiles, had no ‘lineage’ or works-record to rely on! He simply had to believe God! “KNOW YE THEREFORE, that THEY [Abraham and the Gentiles], which are of FAITH [without the Law – without even an obedience to it to show], EVEN THEY, the same (“cursed”), ARE the children of Abraham.” … “Though but a man’s will yet confirmed, it is impossible to annul, or to be added to.” (3:15) This is God’s will and confirmed, by Jesus Christ sacrificed and resurrected, “impossible to annul, or to be added to” – to the Gentiles belong the promises of God! “So then they which be of faith are blessed with faithful Abraham.”
The Gentiles aren’t blessed with the faithful Jews, but they together with the faithful Gentiles, are blessed with the faithful Abraham on the Word of God.
So then, Paul not only proves the Gentiles become heirs of God’s promises by faith only, but the Jews too.
“Now to Abraham (first), and to his seed (after), were the promises made.”
And who are known to be Abraham’s, only, Lawful, “seed”? Who, in fact are, the children “as many as the sand of the sea” of Abraham – “according to the promises of God”? It is CLAIMED, of course, Israel! Does not the Law attest, that the Jews by right of Law are the sons and heirs of Abraham’s blessing? So they boast, and so indeed it is – IF, they believe! It belongs to them by Testament of God – IF, they believed! “In thee (Abraham) shall ALL nation-S, be blessed” – Jews too, but, “together with the FAITHFUL (believing) Abraham”!!
How now? Is their a contradiction; is there a clash of interest? Is it a matter of conditions to the Will, or of changes in the Contract of Confirmation? Does it mean the annulment of the Lawful Document? Who gets done in? Who isn’t paid his due? Who has worked for peanuts? No, it’s all of grace!
“To Abraham, and to his SEED were the promises made. God saith not, And to seeds, as of many; but as of One, And to thy Seed, WHICH IS CHRIST” – “This I say, that the covenant that was confirmed before of God, was confirmed IN CHRIST, and that the Law, which was four hundred and thirty years later, CANNOT disannul God’s Promise, that it should make it of no effect.” “Though but a man’s will yet confirmed, it is impossible to annul, or to be added to.” This though, is God’s will.
[Nobody argues here the other way round, that God’s Promise, annulled the Law, which was four hundred and thirty years later than the Promise! How could the Promise when given have annulled something that not even then existed? It in any case is no how the intent of Paul to argue the ridiculous, as he said in Romans 3:31, consistently, “Do we then make void the Law through faith? God forbid: yea, we (by the faith of the Promise) establish the Law.”]
Now more to the point and specifics:
In 4:3, Paul thinks of himself and his fellow-Jews (where he says), “Even so we, when we, were children”, as over against those reckoned by God but not generally regarded as “child”, “son” “heir” – the Gentiles!
4:1, “Now I (Paul) say, the heir, as long as he is a child (meaning the Jews ‘before faith came’) differs nothing from the servant (meaning the gentiles), though he (the “heir”) be lord (owner by testament) of everything. But he is under tutors and governors until the time appointed of the father (in his testament).
Verse 3 continues with this “heir”, the Jews, supposed as subject, “Even so WE WHEN WE WERE CHILDREN (the Jews / “heirs” not of age yet, and still “a child”, 3:1-2) were in bondage under the elements of the WORLD.” We were just like the Gentiles, without Christ, and as were we pagans. We were no better than them in no respect.
Paul from 4:1 to 4:3 has the Jews in the mind firstly and mainly. The ‘context’ is decidedly ‘Jewish’. Our question is: Does Paul CONTINUE to have the JEWS (exclusively) in mind further on, and through, verses 8 to 11? Will the ‘context’ remain (exclusively) ‘Jewish’? Or does he change subject, and has (exclusively) the Gentiles in mind in verses 8 to 11?
It is no easy question but gets very complex, and one should be wary of too simple answers.
One reason I think that Paul does change subject and context is that he will not unnecessarily repeat (in 8-11) what he has already said (in 1-3). I believe so despite he somehow keeps on writing in the First Person.
4:4, “But when the fullness of the time (“appointed of the Father”, 4:2) was come (as when “faith came”, 3:23) God sent forth His Son, made of a women, made under the Law …”.
Notice “made of a woman” – not of Abraham! God sent forth His Son as a man for men, as the one for the many, as the second Adam for the first Adam. Paul wants to say with this: Jesus Christ was sent by God for Gentiles as for all men, even for the Jews too; but in the first place for all men, and therefore for the Gentiles first: for sinners, specifically and originally!
Notice “made under the Law” – and remember 3:22, “The Scripture has concluded ALL under sin”, and that “we were”, ALL, by the Scripture, “kept under the Law (and) shut up …”!
Paul, saying either “we”, or, “ye”, now and here in this place, in view of the universal principle of divine salvation he takes cognisance of, includes all men, and all men as sinners and unbelievers and Gentiles, as being and for being under that very bondage he has concluded even the Jews were under before “the fullness of the time was come”!
5:1, “To redeem them that were under the Law, that we might receive the adoption of sons”.
Because then, God sent forth Christ to save men being all sinners, Paul including himself “in bondage under the elements of the world” and with the Gentiles including himself, concludes, finally, “To redeem THEM that were under the Law”, sinners, heathen, idolators, Greeks, Hebrews – all the “cursed”. Of whom Paul was chiefest, said he, “that WE, (all) might receive the adoption of sons”.
Paul does NOT speak of Jews in 4:5; he speaks of US, all and everyone of US, men, as Gentiles! And if not as of Gentiles, then in vain did God send forth His Son! Then “verily righteousness should have been by the Law”! God save you my friend, and me, as men, fallen and accursed men – as Gentiles – or not at all!
What Paul PREACHES here in 4:5, saying, “them that were under the Law”, is, that a Jew, should first become a Gentile, a man merely, an ordinary human being – a sinner ultimately – or he cannot become a chosen of God, for “God justif(ies) the HEATHEN through faith” (3:8) – not the Jews through the Law! That is how God, “PREACHED the Gospel before to Abraham”. There is no other Gospel proclaimed; this, is the only! God saves them that are SINNERS, Gentiles, “under the Law”.
In verse 5 therefore, Paul changes both subject and context. He here reasons as were he a Gentile, so that when saying “we” or “ye”, he means the Gentiles. So that even when saying “sons”, it is the heathens or Gentiles he means are the “sons”. How else would any Gentile be saved; how else any man for that matter, even were he a Jew?
Paul THUS ONLY is able to with absolute confidence declare:
4:6, “And because YOU are sons (= had been sons, since by Promise and Blessing God’s to Abraham before the Law and before any Jew), God hath sent forth the Spirit of His Son into your heart, crying, o Father our own Father!”
Context? No, not ‘Gentile’, but of those saved by grace only and not by the works of the Law!
4:7, “Wherefore thou art NO MORE A SERVANT, but a son”!
Whom does Paul here suppose? Gentiles, who previously in fact had been servants, even the servants of the Jews? Yes, but just as much does Paul here think of all men as Jews, who, for their works of the Law, were servants, and in bondage, as he has said in 4:3, “in bondage under the elemental things of the world” – Jews who so in effect were servants to the Gentiles! Or Paul thinks of both Gentiles and Jews for being in bondage together and without distinction – of both as servants, under the bondage of sin and death.
Paul supposes Gentiles, spiritually.
Then follows verses 8-11, and we must admit, the context and the subject “ye” are ‘Gentile’; or salvation is by the Law, and not of grace, for reason of all and every of the arguments above, the main argument being that Paul means the Jews, as in bondage under the elements of the world!
Since salvation then is by grace through the faith of the Promise and Blessing of God, not by the works of the Law, Paul in verse 8 further supposes Gentiles as were they in their former state, of being without Christ, and lost, and worshipping their erstwhile gods that were no gods, but the weak and beggarly elements of the world: “Ye worship days, months, seasons, years”, in vain! “In vain have I laboured so much for you!”
THERS WHO DIDN'T? I have to PROVE that there were Jews still opposing the Gospel? Wow! What a spin on history!” 
