When Paul wrote these words to Timothy, they were in the midst of his foreboding prophecy of coming apostasy and persecution. Furthermore, he knew that he himself would soon be executed, and that these might well be his final teachings to his young disciple and to others through him.
It is remarkable that in such a setting the Spirit of God impelled him to use the example of his own life as the best and most fitting climax to his great ministry. "Just keep on believing and doing what I have been teaching you - that which you have seen put into practice in your own life." These teachings and practices had just been recounted in verses 10-11, and what a remarkable summary they provide of a genuine Christian life.
Doctrine - my teachings, sound and true to God's Word;
Manner of life - my Christ-like behavior and habits;
Purpose - my sole aim, to honor God and do His will;
Faith - my faithfulness to His Word and its demands;
Longsuffering - my patient forbearance;
Charity - my showing true Christian love;
Patience - my cheerful endurance in hard times;
Persecutions - the unjust opposition heaped upon me;
Afflictions - sufferings and tortures which I endured.
The apostle Paul had maintained this strong and consistent Christian testimony for over 30 years following his conversion and could, in all good conscience and true humility, cite his own example as a true teaching aid for others to study and follow.
May Paul's example be ours, and may our lives likewise become true examples of Christianity for any who are watching us today.