Rom 15:8 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:
Yes--
The Fathers of the elect of Israel of the OT are the same Fathers of the faithful of the NT.
Eph 2:11 Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands;
Eph 2:12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
Eph 2:13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
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 2:15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
Eph 2:16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
Eph 2:17 And came and preached peace to you which were afar off, and to them that were nigh.
Eph 2:18 For through him we both have access by one Spirit unto the Father.
Eph 2:19 Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God;
Eph 2:20 And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;
Eph 2:21 In whom all the building fitly framed together groweth unto an holy temple in the Lord:
Eph 2:22 In whom ye also are builded together for an habitation of God through the Spirit.
Gal 3:26 For ye are all the children of God by faith in Christ Jesus.
Gal 3:27 For as many of you as have been baptized into Christ have put on Christ.
Gal 3:28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
Gal 3:29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
Paul writes to the Corinthian brethren--
1Co 10:1 Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea;
1Co 10:2 And were all baptized unto Moses in the cloud and in the sea;
1Co 10:3 And did all eat the same spiritual meat;
1Co 10:4 And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ.
LA