"This command I entrust to you, Timothy, my son, in accordance with the prophecies previously made concerning you, that by them you fight the good fight, keeping faith and a good conscience, which some have rejected and suffered shipwreck in regard to their faith." 1 Timothy 1:18-19
Hmmm ...having faith to fight the good fight. What does that mean?
Prophecies made in Scripture should give us the confidence to rely upon the blessings that we should count on to live powerful, loving lives. The book of Acts is full of examples of people who have made use of the power of the Holy Spirit. Peter, Barnabas, Saul/Paul, Stephen, just to name a few. Peter, as you remember, denied Jesus; yet, Jesus still entrusted to him the command to tend and feed His sheep.
Even as we have made previous mistakes in our lives, being prodigal and selfish before our loving Father and His loving Son, the Holy Spirit still indwells those who believe in Christ as their Savior. The problem most of us have is having the faith to fight the good fight. Our training (the society we live in which helps produce the mistakes our parents made, the mistakes our teachers made, the mistakes our government made, the mistakes we make) gets in the way of our faith. This training explains a part of "the shipwreck," because we rely more upon this training rather than our faith in God's Word and promises. We lose our light and saltiness.
We are to be the salt (halas in Greek) of the earth (see Matthew 5:13-15). Salt, with it's purifying, antiseptic qualities is still a symbol of friendship and fidelity in many mid-eastern countries. Believers are to be the antiseptic that cleanses the worldly training people have received.
Paul instructed Timothy to have confidence in the promises of God. We must, as well, have the faith to be inspired and aided by God's promises, relying upon the abilities He tells us we have and instructs us to use. We are more than conquerors in Christ, even when our surroundings seem to be so intimidating, bigger than we think we can handle. God promised us! We must fight the good fight by trusting God's Word ... He can not lie!
Read 2 Timothy 2:3-4, Acts 23:1-5, 2 Corinthians 10:3-4, Galatians 3:24, Titus 1:1-3 for more illumination.