Paul uses metaphor when he’s speaking of the “helmet of salvation.” Being saved, through faith, by God’s marvelous grace, there is protection from the onslaughts of the enemy. Our focus should be on our failures but on the 
victory that will ultimately be ours regardless of the circumstances of our present moment. In 1 Thessalonians 5:8, Paul tells them and us, “…let us be sober, having put on the breastplate of faith and love, and for a helmet the hope of salvation.” We have a guarantee of victory. Believers come with an unbreakable warranty written by God in the blood of His son. It goes into effect the moment we put our faith in Christ.
In the 1600’s, Oliver Cromwell, known as the Lord Protector of England, had never lost a battle. It’s often argued that his victory through all kinds of adversity was the result of his trust in God and the Salvation which awaits him after this life. Boice says that Cromwell and his army , “…knew that their destiny was secure and that they were fighting because God had led them to that spot and would prosper them in that work. There is a sense in which that should be true of us. True, we suffer setbacks in our attempts to live the Christian life. Even Paul said that he was sometimes tripped up by Satan’s onslaughts: ‘hard pressed … perplexed … persecuted … struck down’ (2 Cor. 4:8–9). But these momentary setbacks are not the end, nor are they even utter defeats. For Paul said, ‘We are hard pressed on every side, but not crushed; perplexed, but not in despair; persecuted, but not abandoned; struck down, but not destroyed. … Therefore we do not lose heart. Though outwardly we are wasting away, yet inwardly we are being renewed day by day. For our light and momentary troubles are achieving for us an eternal glory that far outweighs them all. So we fix our eyes not on what is seen, but on what is unseen. For what is seen is temporary, but what is unseen is eternal’ (2 Cor. 4:8–9, 16–18).”
What was true for Cromwell and his men is also true for all believers. The battles come! They press us. The corner us! They assault our joy! They confuse us! They bring doubt! They bring discouragement! They bring Depression! And, unlike what was said of Cromwell, we even lose battles. We experience occasional defeat. It’s well known that In 1831, Abraham Lincoln failed in business. In 1832, Abraham Lincoln was defeated for state legislator. In 1833, Abraham Lincoln tried a new business, and failed. In 1835, Abraham Lincoln’s fiancée died.
In 1836, Abraham Lincoln had a nervous breakdown. In 1843, Abraham Lincoln ran for congress and was defeated. In 1848, Lincoln ran again, and was defeated; again. In 1855, Lincoln ran for the Senate, and lost.
In 1856, Lincoln ran for Vice President, and lost. In 1859, Lincoln ran again for the Senate. He was defeated. But all that doesn’t matter. We know the ultimate result! God guarantees our ultimate victory. Just as Abraham Lincoln was elected president in 1860 and has come down to us in history as one of the greatest of our presidential leaders, so too, we’ve won God’s election! We too will have ultimate victory!