Romans 15:25-27 — But now I go unto Jerusalem to minister unto the saints.
For it hath pleased them of Macedonia and Achaia to make a certain contribution for the poor saints which are at Jerusalem.
It hath pleased them verily; and their debtors they are. For if the Gentiles have been made partakers of their spiritual things, their duty is also to minister unto them in carnal things.
When therefore I have performed this, and have sealed to them this fruit, I will come by you into Spain.
And I am sure that, when I come unto you, I shall come in the fulness of the blessing of the gospel of Christ.
Macedonia and Achaia — the churches all over Greece
minister (verse 25) — as a deacon, not as a priest
poor in Jerusalem — contrast with Acts 4:34 (Neither was there any among them that lacked: for as many as were possessors of lands or houses sold them, and brought the prices of the things that were sold.) The kingdom was rejected by the Jews and now, only 20 or so years later, they were suffering.
Paul did make it to Rome, but in chains, and he was shipwrecked on the way. But while in prison there, he was able to write Philippians 1:12 — But I would ye should understand, brethren, that the things which happened unto me have fallen out rather unto the furtherance of the gospel.