"But is now made manifest by the appearing of our Saviour Jesus Christ, who hath abolished death, and hath brought life and immortality to light through the gospel: Whereunto I am appointed a preacher, and an apostle, and a teacher of the Gentiles. For the which cause I also suffer these things: nevertheless I am not ashamed: for I know whom I have believed, and am persuaded that he is able to keep that which I have committed unto him against that day."
Every part of the Christian life revolves around faith. We are saved by grace through faith, and we walk by faith. We win the victory through faith. And there is almost nothing the devil attacks more, because he knows that doubt is deadly, than faith. Faith does not depend on evidence, but that does not mean that is an uncertain foundation. “Now faith is the substance of things hoped for, the evidence of things not seen” (Hebrews 11:1).
God wants us to be settled and certain in our faith. Paul endured great hardship and suffering because of his fearless preaching, but he did not let that keep him from trusting God. When he wrote his final letter to Timothy, he was again in jail in Rome, knowing that his life would soon be ended. Yet even then he could say with confidence that he was persuaded of God's ability to fulfill every promise. Some things in life may be doubtful, but faith in God should not be one of them.
Horatius Bonar said, “Uncertainty as to our relationship with God is one of the most enfeebling and dispiriting of things. It makes a man heartless. It takes the pith out of him. He cannot fight; he cannot run. He is easily dismayed and gives way. He can do nothing for God. But when we know that we are of God, we are vigorous, brave, invincible. There is no more quickening truth than this of assurance.”
We cannot accomplish the work God has placed before us unless we are willing to continue in the spiritual fight by His grace.