Passage
Erastus did remain in Corinth, and Trophimus I left in Miletus infirm;
Erastus did remain in Corinth, and Trophimus I left in Miletus infirm;
2 Timothy 4:18 and the Lord shall free me from every evil work, and shall save <FI>me<Fi> --to his heavenly kingdom; to whom <FI>is<Fi> the glory to the ages of the ages! Amen.
2 Timothy 4:19 Salute Prisca and Aquilas, and Onesiphorus' household;
2 Timothy 4:20 Erastus did remain in Corinth, and Trophimus I left in Miletus infirm;
2 Timothy 4:21 be diligent to come before winter. Salute thee doth Eubulus, and Pudens, and Linus, and Claudia, and all the brethren.
2 Timothy 4:22 The Lord Jesus Christ <FI>is<Fi> with thy spirit; the grace <FI>is<Fi> with you! Amen.
The verse centers on "erastus", "remain", "corinth", "trophimus", "left", "miletus", and "infirm". It is saying that the verse draws attention to "erastus" and "remain", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 19's "Salute Prisca and Aquilas and Onesiphorus' household..." into verse 21's "be diligent to come before winter Salute...", so "erastus" and "remain" belong inside that flow. In 2 Timothy context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "erastus" and "remain" with trust shaped by these words, not by a vague optimism outside the passage.