25 But now I am going to Jerusalem to minister to the saints.
26 For it pleased those from Macedonia and Achaia to make a certain contribution for the poor among the saints who are in Jerusalem.
27 It pleased them indeed, and they are their debtors. For if the Gentiles have been partakers of their spiritual things, their duty is also to minister to them in material things.
28 Therefore, when I have performed this and have sealed to them this fruit, I shall go by way of you to Spain.
29 But I know that when I come to you, I shall come in the fullness 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.