Compare 1 Tim. 6:12. While fighting “the good fight” and running “the course” that God had assigned him, Paul had the satisfaction of knowing that, though he had often faced great hardships and temptations, he had not failed to guard and preserve the faith entrusted to him (see on 1 Tim. 1:11; 2 Tim. 1:12). Paul’s example of faithfulness was to be a challenge to Timothy and to every future minister of the gospel. Personal faith depends upon adherence to God’s Word. Every Christian will “guard the faith” by his personal representation of its principles. The sincerity of a Christian’s personal faith is measured by the extent to which he reflects these principles.

Gr. tēreō, “to guard.”

 That is, the course of life that God has appointed him. Paul had fulfilled God’s plan for him; he did not slacken or falter, he met every challenge, even his execution, with Christian buoyancy and resoluteness. Compare Acts 20:24. For the extent of the church at the close of Paul’s ministry see The Church at the Close of Paul’s Ministry.

 Literally, “the good fight.” The definite article emphasizes that supreme fight “of faith” (see on 1 Tim. 6:12) in which all Christians are engaged.

 Compare 1 Tim. 6:12. Paul’s commitment to be Christ’s ambassador involved a life of constant warfare with the forces of evil, whether men or demons (see on 1 Cor. 9:25; Phil. 1:27, 30; 1 Thess. 2:2). The apostle wore well the “whole armour of God” as he bravely stood “against the wiles of the devil” (Eph. 6:11).