Romans 15:25

Paul wants the Romans to understand that they ought to be concerned with this sort of thing, for those who live because of mercy and who are justified before God ought to show their devotion to their brothers.

Since he had said that I have no longer "more place in these parts," and, "I have a great desire, these many years, to come unto you," but he still intended to delay; lest it should be thought that he was making a jest of them, he mentions the cause also why he still puts it off, and he says, that "I am going unto Jerusalem," and is apparently giving the excuse for the delay. But by means of this he also makes good another object, which is the exhorting of them to alms, and making them more in earnest about it. Since if he had not been minded to effect this, it had sufficed to say, "I am going unto Jerusalem." But now he adds the reason of his journey. "For I go," says he, "to minister to the saints." And he dwells over the subject, and enters into reasonings, and says that they "are debtors," and that, "if the Gentiles have been made partakers of their spiritual things, their duty is also to minister unto them in carnal things," that they might learn to imitate these. Wherefore also there is much reason to admire his wisdom for devising this way of giving the advice. For they were more likely to bear it in this way than if he had said it in the form of exhortation; as then he would have seemed to be insulting them, if, with a view to incite them, he had brought before them Corinthians and Macedonians. Indeed, this is the ground on which he does incite the others as follows, saying, "Moreover, brethren, we do you to wit of the grace of God bestowed on the Churches in Macedonia." (2 Cor. viii. 1.) And again he incites the Macedonians by these. "For your zeal," he says, "hath provoked very many." (ib. ix. 2.) And by the Galatians in like manner he does this, as when he says, "As I have given order to the Churches of Galatia, even so do ye." (1 Cor. xvi. 1.) But in the case of the Romans he does not do so, but in a more covert way. […]

"But now I shall set out for Jerusalem to minister to the saints. For it has pleased Macedonia and Achaia to make a certain contribution for the poor of the saints who are in Jerusalem. For it has pleased them, and they are their debtors: for if the Gentiles have been made partakers of their spiritual things, they ought also to minister to them in carnal things."

Above he gave a promise to come to them. In the meantime he still needed to delay. Therefore, lest they think he was mocking them, he states the reason for his delay and says: "I go to Jerusalem to minister to the saints." He did …

Then when he says, but now I shall go, he tells why he must postpone his visit. In regard to this he does three things: first, he gives the reason, saying: but now I shall go, i.e., I am not coming to you at once, …