Gill helps me to see more clearly how this book will progress:
The design of it is to stir up Timothy to the faithful and diligent discharge of his duty, as a minister of the Gospel; to abide constantly by the truths of it, and to animate him to suffer patiently, cheerfully, and courageously for the sake of it; and to warn him against false teachers, and their errors, who were already risen, and would afterwards arise, and be followed by such who had itching ears, and could not bear sound doctrine; but this should be no discouragement to him in the prosecution of his work; and lastly to desire his presence with him at Rome, being now destitute of his several assistants.This is probably the last book that Paul wrote. Paul is an old man now, aware that his time on earth is growing shorter. He writes to Timothy encouraging him as a Christian.
JFB has this to say:
Paul was anxious to see his disciple Timothy, before his death, and that Timothy should bring Mark with him (2Ti_1:4; 2Ti_4:9, 2Ti_4:11, 2Ti_4:21). But feeling how uncertain it was whether Timothy should arrive in time, he felt it necessary, also, to give him by letter a last warning as to the heresies, the germs of which were then being scattered in the Churches. Hence he writes a series of exhortations to faithfulness, and zeal for sound doctrine, and patience amidst trials: a charge which Timothy seems to have needed, if we are to judge from the apostle’s earnestness in urging him to boldness in Christ’s cause, as though Paul thought he saw in him some signs of constitutional timidity (2Ti_2:2-8; 2Ti_4:1-5; 1Ti_5:22, 1Ti_5:23).And PNT adds this:
Timothy, his "beloved son" in the gospel, was still laboring in distant Ephesus, but the aged apostle, about to go to rest from his weary labors, desired to see him once more in the flesh. Hence, he bids him come, as speedily as possible; but, lest he might arrive too late to receive his parting words, he impresses upon him in this letter, with the earnestness of a last charge, the various duties of his office, and especially of opposing the dangerous heresies which threatened to destroy the vitality of the Christian religion.Overall, it sounds like a book relevant for the age we live in. May I learn much from it and take it all to heart.