In many international matches in games like cricket or football you might have seen some BIG teams trounce some other teams. The losing teams would have had plenty of talent; yet they end up losing. If you analyze the reason for defeat, it would surprise you to note that the game was lost for the losers even before the game had actually begun!
The trouble was in their minds. They believed that it was impossible for them to defeat the big team. Not only that they feared their opponents. This fear paralyzed them from acting the right way at the right time. Instead of putting up a strong fight for the crown, they meekly succumbed to the victors. They had enough talent and ability to defeat their opponents, but the inability to conquer the fear of their opponents holding sway in their minds led to their defeat. So the game was over for the losers even before it began. The victors had nothing much to do other than feast on the spoils!
In Deuteronomy chapter 20 (v.1-4), God gave specific instructions to the Israelites in this regard. He asked them not to be afraid when they saw horses and chariots and an army greater than theirs as they went to war against their enemies. Instead God wanted them to remember that He was with them to give them victory. Likewise, we should always remember that God is with us to fight for us and give us victory over sin. The enemy will always try to frighten us by showing his power in many ways. Yielding to such kind of fear brings sure defeat. Be bold in the Lord. Face the enemy with the sure knowledge that God is with you. Then victory is yours!