Paul admonishes Timothy to fight the good fight of faith. The analogy is not by accident. We are in a spiritual war. Remember Ephesians 6:10-18 opens our eyes to the fact that we are not battling with men, but against principalities, against powers, against spiritual hosts of wickedness in heavenly places. How does one battle what one cannot see?
We use the spiritual weapons God has given us. We start by standing firm having been wrapped in Truth (saturated in God's Word), having out on the armor (protective gear) of righteousness (doing what is right regardless of other people's actions), wearing the shoes if the preparation of the gospel of peace, (being ready to share God's invitation if forgiveness as soon as the person who is standing against us is ready to hear it).
The most important weapon, Paul says, is the shield of faith by which we quench the fiery darts of the evil one (Ephesians 6:16), and use the sword, which is the Word of God. At all times during your battle, remember to pray for other believers who are also on battles around the world.
Often remind yourself "greater is he that is in us, than he that is in the world" (1John 4:4).
