Although Paul was writing to a largely Gentile audience, he still quotes Jewish scriptures:
Therefore I will confess you among the Gentiles, and sing praises to your name (see Psalm 49:1).[with thanks to the editors of the Wesley Study Bible for locating the sources for me]
Praise the Lord, all you Gentiles, and let all the peoples praise him (see Psalm 117:1).
The root of Jesse shall come, the one who rises to rule the Gentiles; in him the Gentiles shall hope (see Isaiah 11:10).
One way we can read this passage is with satisfaction that we can be Christian without first having to be Jews. But, another way to read it is to consider who might be included in Christ's care other than whatever particular tight circle we inhabit.
That is, do we in the church consider that Christ's mercy to us is intended to be instructive to onlookers? How welcoming are to those outsiders anyway? How can we expect them to know what Christ has done if we are keeping it a secret in house anyway?
Paul's understanding was that God had always intended to include Gentiles. Who are today's Gentiles? How intentionally inclusive are we?