21 When these things were accomplished, Paul purposed in the Spirit, when he had passed through Macedonia and Achaia, to go to Jerusalem, saying, “After I have been there, I must also see Rome.”
22 So he sent into Macedonia two of those who ministered to him, Timothy and Erastus, but he himself stayed in Asia for a time.
Spirit (v.21) — should be “spirit” (lower case) — Paul’s spirit, not the Holy Spirit — he was firmly resolved
into Macedonia (v.22) — to collect for those in Jerusalem (2 Corinthians 8:1-5)
The question has often been raised how the purposing of Paul in the spirit to go again to Jerusalem is to be understood. Is the word “spirit” to be written with a capital “S” or not? In other words, did he purpose in the Spirit of God after prolonged prayer, to go up to Jerusalem? Did the Holy Spirit guide him to take up to the city of his fathers the contributions from Achaia and Macedonia for the poor saints? (Romans 15:25-26). It could not have been the Spirit of God who prompted him to go once more to Jerusalem, for we find that during the journey the Holy Spirit warned him a number of times not to go to Jerusalem. These warnings were not heeded, but they prove conclusively that Paul purposed in his own spirit. He was called to evangelize; to continue to preach the glorious Gospel, and it was a turning aside from the great ministry committed unto him. but behind his burning desire to go up to Jerusalem stood the mighty constraint of love for his own beloved brethren.
This holy love and courage prompted him to say, when once more his brethren had besought him by the Spirit not to go up to Jerusalem, “What mean ye to weep and break my heart? for I am ready not to be bound only, but also to die at Jerusalem for the name of the Lord Jesus” (Acts 21:13). And the Lord in His mercy, who knows the motives of the heart, over-ruled the error of His servant. Later from the prison in Rome, Paul could write in his joyous epistle to the Philippians, “But I would ye should understand, brethren, that the things which happened unto me have fallen out rather unto the furtherance of the Gospel; so that my bonds in Christ are manifest in all the palace, and in all other places (Philippians 1:12-13). — The Acts of the Apostles, by Arno C. Gaebelein, pages 333-334.
The epistle which we know as First Corinthians, then, was almost certainly written between the public bonfire of Acts 19:19 and the uproar over Diana, or during the “season” referred to in verse 22. Evidently the church at Ephesus, or a segment of it, met in the home of Aquila and Priscilla at this time (1 Corinthians 16:19).
The plan to visit Macedonia and Achaia again was doubtless largely due to continued disturbing reports from the church at Corinth. — Acts Dispensationally Considered, by C.R. Stam, page 179.
Erastus (v.22) — Probably to be identified with the person of that name in 2 Timothy 4:20, where also he appears to be Paul’s fellow-worker, having recently proceeded to Corinth at the time of the latter’s second Roman imprisonment. He is, it would seem, to be distinguished from the Erastus of Romans 16:23, since the office of “treasurer of the city” (of Corinth), if he still held it, would hardly be compatible with an itinerant missionary life. — The Acts of the Apostles, by Thomas Walker, page 418-419.