Before Paul heads to Spain, Romans 15:25-29 tells us, he will return to Jerusalem with a bundle of money and gifts for the saints in Jerusalem. Wright sees the theology of Paul, as expressed in Romans (esp 14–15), in this collection for the saints.
Paul spent energies on collecting funds for the saints in Jerusalem. There are all kinds of debates about that collection, and Wright disagrees with one of the points I make in my article (that it had an eschatological shape to it) — but who am I when it comes to Pauline scholarship?, but Wright’s point is certainly central: this gift would demonstrate the unity of Gentiles with Jews in the faith of the Messiah.
Paul’s hope was probably realized in part, though Luke tells us almost nothing (Acts 24:17). What happened was that Paul got arrested and his life took on a new turn: he ended up in that prison above the Roman forum preaching the gospel in Rome, but not as he planned.
He then asks them to pray for him — and that the God of peace may be with them.