Where was God's Grace (towards the gentiles) mentioned in the Old Testament?
Its there - just read Isaiah, for example.
Prophesied Grace -
Israel's rise, then the Gentiles.
Paul touches on this in Romans 15:8-12.
8. Now I say that Jesus Christ was a minister
of the circumcision for the truth of God,
to confirm the promises made unto the fathers:
9.
And that the Gentiles might glorify God for his mercy;
as it is written, For this cause I will confess to thee
among the Gentiles, and sing unto thy name.
10.
And again he saith, Rejoice, ye Gentiles,
with his people.
11.
And again, Praise the Lord, all ye Gentiles;
and laud him, all ye people.
12. And again, Esaias
saith, There shall be a root of Jesse, and he that shall rise to reign
over the Gentiles;
in him shall the Gentiles trust.
He has already related that is on hold, in 9-11.
Thus; the sense of 15:13's "
Now the God of
hope...", at which point he relates
his ministry among the Gentiles
"not where Christ was named," etc.
In this, my own understanding is that that was not the Mystery [though the Mystery was also related to the Cross] that was revealed only to and through the Apostle Paul.
Paul was born out of Israel's due time
Prophesied Grace., 1 Cor. 15:8; in contrast to 1 Peter 1:9-13, etc.
Note the Gentile's
Prophesied Grace in the following, for example - Mark 7:
24. And from thence he arose, and went into the borders of Tyre and Sidon, and entered into an house, and would have no man know it: but he could not be hid.
25. For a certain woman, whose young daughter had an unclean spirit, heard of him, and came and fell at his feet:
26.
The woman was a Greek, a Syrophenician by nation; and she besought him that he would cast forth the devil out of her daughter.
27. But Jesus said unto her,
Let the children first be filled: for it is not meet to take the children's bread, and to cast it unto the dogs.
28. And she answered and said unto him, Yes, Lord: yet the dogs under the table eat of the children's crumbs.
29. And he said unto her, For this saying go thy way; the devil is gone out of thy daughter.
30. And when she was come to her house, she found the devil gone out, and her daughter laid upon the bed.
Only when she acknowledge Israel's priority, did He then allowed that nation's blessing to overflow to her.
I've already noted that the Apostle Paul also understood this - compare the following, as well.
Isaiah 60:
1. Arise, shine; for thy light is come, and the glory of the LORD is risen upon thee.
2nd Coming...
2. For, behold, the darkness shall cover the earth, and gross darkness the people: but the LORD shall arise upon thee, and his glory shall be seen upon thee.
Then the Gentiles, through Israel's rise...
3. And the Gentiles shall come to thy light, and kings to the brightness of thy rising.
Isaiah 66:
19. And I will set a sign among them, and I will send those that escape of them unto the nations, to Tarshish, Pul, and Lud, that draw the bow, to Tubal, and Javan,
to the isles afar off, that
have not heard my fame, neither have seen my glory; and they shall declare my glory among the Gentiles.
Note Paul's words in Acts 13, actually understood in Romans 11.
Acts 13:
44. And the next sabbath day came almost the whole city together to hear the word of God.
45. But when the Jews saw the multitudes, they were filled with envy, and spake against those things which were spoken by Paul,
contradicting and blaspheming.
46. Then Paul and Barnabas waxed bold, and said, It was necessary that the word of God
should first have been spoken to you: but seeing ye put it from you, and judge yourselves unworthy of everlasting life, lo, we turn to the Gentiles.
47. For so hath the Lord commanded us,
saying, I have set thee to be a light of the Gentiles, that thou shouldest be for salvation unto the ends of the earth.
48. And when the Gentiles heard this, they were glad, and glorified the word of the Lord: and as many as were ordained to eternal life believed.
Verse 46 and 47 refers to Israel's
Prophesied commission among the Gentiles. And how that God
had turned from that for Israel's blasphemy against the Spirit.
Romans 9-11 will later relate that said turning from Israel is temporary.
This "to the Jew first" is the issue of God's testimony through this odd new Apostle, that He has turned from Israel, at the same time that it is Paul's hope that he might save some, even as Israel continues to diminish away "for a season."
My understanding is that the Mystery has nothing to do with that
Gentile Grace that was
Prophesied. It foresees Israel's
rise, not her
fall.
Some see that differently, and that is fine. We are each at our own level of understanding these things,within Mid-Acts.
We should explore these things, at the same time "let every man be fully persuaded in his own mind," Roman 14:5.
"Him that is weak in the faith receive ye, but not to doubtful disputations" verse 1.
For its principle still applies - Galatians 6:
1. Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted.
2. Bear ye one another's burdens, and so fulfil the law of Christ.
3. For if a man think himself to be something, when he is nothing, he deceiveth himself.
4. But let every man prove his own work, and then shall he have rejoicing in himself alone, and not in another.
5. For every man shall bear his own burden.
When that continually fails, this kicks in - Romans 16:
17. Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them.
18. For they that are such serve not our Lord Jesus Christ, but their own belly; and by good words and fair speeches deceive the hearts of the simple.
An aspect of causing divisions and offences contrary to the doctrine, is the very tactic of those who serve not our Lord Jesus Christ, but their own belly... "that they may glory in your flesh," Gal. 6:13.
You don't strike me as that, so bring on what differences you might care to explore