In Acts 19:22 we read that Paul sent Timothy and Erastus into Macedonia while “he himself stayed in Asia for a while.” His purpose for sending them was to prepare for his coming, especially in regard to the offering which he was taking up for the saints in Judea. From Macedonia they were to continue into Achaia (see 1 Cor 4:17 and 16:10-11), which makes sense considering that Erastus was evidently from Corinth (see Romans 16:23 which was written from Corinth, and 2 Tim 4:20). Shortly after sending them Paul wrote 1 Corinthians mentioning that they should expect Timothy and to “send him on his way in peace, so that he may come to me; for I expect him with the brethren” (1 Cor 16:11). As Paul was himself soon heading to Macedonia (Acts 19:21, 1 Cor 16:5) it was along this path that he expected to receive Timothy back. Thus, after accompanying Erastus to Corinth to look into the issues that had arisen there, as well as to encourage them in regard to the offering Paul was taking up for the Judean saints, Timothy was to head north again with some brethren to rejoin the apostle wherever the timing of their travels would allow them to meet.
Likely included among these brethren was Titus, who it appears had some closer relationship to the Corinthians than Timothy, and had perhaps been there for some longer time ministering to them on Paul’s behalf (cf. 2 Cor 2:13, 7:6,13,14, 8:6,16,23, 12:18, and contrast 1 Cor 16:10-11). It was perhaps even Titus whom Paul sent with 1 Corinthians, and who would be most able to report back to him about its reception and effect upon them.
It was also at this time that “there arose no small disturbance concerning the Way” which we read about in Acts 19:23-41 (see also 2 Tim 4:14). Paul mentioned the trouble that was brewing in 1 Cor 16:9, then recounts the affliction they faced in 2 Cor 1:8. Luke records that “after the uproar had ceased, Paul sent for the disciples and when he had exhorted them and taken his leave of them, he departed to go to Macedonia” (Acts 20:1), traveling north through Troas. However, not finding Titus in Troas, which Paul evidently thought likely given the time that had elapsed, he went on to Macedonia eagerly seeking and concerned about what news Titus and Timothy might bring in regard to the Corinthians, and this in spite of a door of opportunity that had opened for the gospel (see 2 Cor 2:12-13). Thus meeting up with them in Macedonia, Paul received good news that greatly comforted the apostle in his concern for the Corinthians, that the letter he had written had produced its desired effect of a sincere repentance (see 2 Cor 7:5-16).
It was at this time that Paul wrote 2 Corinthians, rejoicing in the comfort Titus had brought, while at the same time preparing them for his much awaited visit. For he wanted them to be prepared to make good on the offering for the saints in Judea which he had already discussed with them (see 2 Cor 8-9). And although the news Titus brought comforted the apostle, it was also clear that the crisis was by no means entirely resolved, and some were still challenging his authority. In the first chapter he is forced to defend his change in plans to visit Macedonia first instead of Corinth (see 1 Cor 16:5, 2 Cor 1:15-23). In the latter chapters of his letter Paul also asked that “when I am present I may not be bold with the confidence with which I propose to be courageous against some, who regard us as if we walked according to the flesh (10:2) and warns “those who have sinned in the past and … all the rest as well, that if I come again, I will not spare anyone” (13:2).
Having thus “gone through those districts” of Macedonia and “given them much exhortation, he came to Greece. And there he spent three months” before returning through Macedonia (Acts 20:2-3). It was during those three months in Corinth that he wrote his epistle to the Romans (see Rom 16:23, 1 Cor 1:14).