So according to your ideas, the Apostle Paul did not preach the gospel of grace during the Acts period. If that is true then how do you explain the fact that Paul himself says in the book of Acts that he did preach the gospel of grace?:
"But none of these things move me, neither count I my life dear unto myself, so that I might finish my course with joy, and the ministry, which I have received of the Lord Jesus, to testify the gospel of the grace of God" (Acts 20:24).
The epistle to the Romans was written during the Acts period and it is clear to anyone with an open mind that Paul was indeed preaching the gospel of grace in that epistle.
"Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all" (Ro.4:16).
Their basic premise is off; because the information they are basing it on, is INCOMPLETE.
Paul's is a Mystery concerning the Cross work of Christ as to its redemption of men into the Body towards this Body's equally Mystery, purpose.
It is NOT Israel's redemption in the Cross. Paul was un-save-able under that aspect.
Israel's is the Blood as to THEIR New Covenant that said Blood would make possible; the subject of Prophecy - of their PROPHESIED Grace.
In this, information concerning the Blood is THEIR establishment truth in reverse, as they already knew the PURPOSE of their calling.
Theirs was but to believe Christ was/is their PROPHESIED Messiah, NOT that He died for their sins, as that is built into THEIR requirement - believe that He is/was the Christ.
Their Epistles THEN establish them in THEIR understanding of the Blood.
But the Blood itself concerns a Two-Fold Purpose - both aspects of which the Blood would make possible.
There is Israel's, and Gentile redemption under that nation, AS PROPHESIED.
And there is the Mystery's Redemption of Jew and Gentile - not of a nation corporately, nor of nations through Israel's overflow - but of individual Jew and Gentile [independent of Israel's Prophesied redemption] this side of Israel's Prophesied fall and Prophesied temporary setting aside.
The Wrath was headed AS PROPHESIED, BUT then God revealed "a Mystery..."
In this, the mystery in Romans 11:25 is that during Israel's Prophesied, temporary fall, God would do an UNPROPHESIED work among, and directly IN the Gentiles, INDEPENDENT OF that Prophesied aspect of His Two-Fold Purpose among the Gentiles THROUGH Israel's overflow.
In short, a work according to a Mystery.
Paul had wanted to share this with the Corinthians, for example, but they were caught up in "that's not for us" - 1 Cor. 1-3.
Fact is, there is a point in Acts 9 where Paul is saved, goes off to Arabia, learns the Mystery, then returns, there in Acts 9, to preach Christ in His Two-Fold aspect.
We know this, both from his additional info in Galatians 1 as to what happened in Acts 9, as well as from his constant reminder in Romans thru Philemon regarding all he had preached unto them during Acts.
All aspects of the Mystery are found throughout his thirteen epistles - including those he wrote during Acts.
By the time Paul reaches Romans 9, he has covered the basic frame of reference and or general rule of thumb that many of the very basics of both "the gospel of the Grace of God," and its Mystery "new creature" are all about.
I could not see this either. Til I saw the further distinction - that the distinction is NOT between Law and Grace, BUT between Israel's Prophesied Grace "UNDER the Law...BY faith" and the Body's Mystery Grace 'WITHOUT the Law...through faith," Romans 3's summarized in verse. 3:30:
"Seeing it is one God, which shall justify the circumcision
by faith, and uncircumcision
through faith.
The same Two-Fold thought the Apostle Paul relates to those he had taught it to VERY early in his ministry -Galatians 6:
15. For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but
a new creature.
16. And as many as walk according to this rule, peace be on them, and mercy,
and upon
the Israel of God.
Both are found "in Christ Jesus" - a redemptive term that is, nevertheless, different, Dispensationally.