In one of the most famous battles in history David defeats Goliath and single-handedly saves his country's honor. David, the young man, defeats Goliath, the trained warrior who was larger, better equipped, and better trained - at least by the rules of warfare in that day.
But in reality, there was a massive mismatch that people couldn't see because they saw the battle through their own understanding. The armies on the battlefield were taught size, armor, shield bearers and heavy armor piercing spears won wars. David didn't have any of those things, but he did have the ability to use a sling with such accuracy and force that he could kill lions and bears. David's strength and skills were exactly what could defeat Goliath. David saw this and he convinced Saul to let him represent Israel to defeat Goliath.
There was another mismatch that is even more impressive in my opinion. God had prepared David for this fight. Leading up to this battle David had been anointed by Samuel and from that day forward David had the presence of the Lord with him always. David also spent his time tending and protecting sheep in the wilderness. Here he learned how to kill the lion and the bear, and protect what he is charged to watch over. This time in the wilderness is also when David spent time with God and learned from God.
As the rest of the world saw a young man carrying bread and cheese to the battlefield, God and all the angels on heaven and earth watched the mightiest warrior of the day approach his biggest victory yet.
Can you imagine a sniper walking onto that battlefield with a .50 caliber that had just been zeroed to 3000 meters? That sniper would say, "Let me take the shot!!" This is exactly what David asked Saul when he proclaimed, "your servant will go and fight him." -1 Samuel 17:32. David was ahead of his time because the Lord trained him.
Today, we can all have access to the Lord through Jesus Christ. Jesus himself will train you and lead you into your battles and keep you ahead of your enemies. He will teach you things that your eyes have never read nor your ears ever heard. He will lead you to victory through the everyday life you have before you.
If you're finding yourself continually behind the curve and unable to get ahead of your enemies, stop trying harder and spend more time with God. He is good to train you and prepare you for victory.