Oh Please. Is that why Jesus spent three years with His JEWISH disciples before His crucifixion.
Romans is universally speaking to both Jews and Gentiles.
Again for good measure...
Romans 7:6 But now we have been released from the law, because we have died to what controlled us, so that we may serve in the new life of the Spirit and not under the old written code.
The Jews hated their brothers of the House of Israel. Thus in the New Testament those of the House of Israel are called Gentiles. Paul even made that point.
Rom_11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until t
he fulness of the Gentiles be come in.
Paul is again quoting from the OT.
Gen 48:9 And Joseph said unto his father, They are my sons, whom God hath given me in this place. And he said, Bring them, I pray thee, unto me, and I will bless them.
Gen 48:10 Now the eyes of Israel were dim for age, so that he could not see. And he brought them near unto him; and he kissed them, and embraced them.
Gen 48:11 And Israel said unto Joseph, I had not thought to see thy face: and, lo, God hath shewed me also thy seed.
Gen 48:12 And Joseph brought them out from between his knees, and he bowed himself with his face to the earth.
Gen 48:13 And Joseph took them both, Ephraim in his right hand toward Israel's left hand, and Manasseh in his left hand toward Israel's right hand, and brought them near unto him.
Gen 48:14 And Israel stretched out his right hand, and laid it upon Ephraim's head, who was the younger, and his left hand upon Manasseh's head, guiding his hands wittingly; for Manasseh was the firstborn.
Gen 48:15 And he blessed Joseph, and said, God, before whom my fathers Abraham and Isaac did walk, the God which fed me all my life long unto this day,
Gen 48:16 The Angel which redeemed me from all evil, bless the lads; and let my name be named on them, and the name of my fathers Abraham and Isaac; and let them grow into a multitude in the midst of the earth.
Gen 48:17 And when Joseph saw that his father laid his right hand upon the head of Ephraim, it displeased him: and he held up his father's hand, to remove it from Ephraim's head unto Manasseh's head.
Gen 48:18 And Joseph said unto his father, Not so, my father: for this is the firstborn; put thy right hand upon his head.
Gen 48:19 And his father refused, and said, I know it, my son, I know it: he also shall become a people, and he also shall be great: but truly his younger brother shall be greater than he, and
his seed shall become a multitude of nations.
Gen 48:20 And he blessed them that day, saying, In thee shall Israel bless, saying, God make thee as Ephraim and as Manasseh: and he
set Ephraim before Manasseh.
Multitude = Fulness
Nations = Gentiles
Ephraim was the head of the House of Israel.
Eze_37:16 Moreover, thou son of man, take thee one stick, and write upon it, For Judah, and for the children of Israel his companions: then take another stick, and write upon it, For Joseph,
the stick of Ephraim, and for all the house of Israel his companions:
Eze_37:19 Say unto them, Thus saith the Lord GOD; Behold, I will take
the stick of Joseph, which is in the hand of Ephraim, and the tribes of Israel his fellows, and will put them with him, even with the stick of Judah, and make them one stick, and they shall be one in mine hand.
Which the above is also addressed by Paul in the NT.
Eph_2:14 For he is our peace, who hath made
both one, and hath broken down the middle wall of partition between us;
Eph_2:16 And that he might
reconcile both unto God in one body by the cross, having slain the enmity thereby:
Eph_2:18 For through him
we both have access by one Spirit unto the Father.