The reason why many fail in battle is because they wait until the hour of battle. The reason why others succeed is because they have gained their victory on their knees long before the battle came.

Anticipate your battles; fight them on your knees before temptation comes, and you will always have victory. We are too busy to pray, and so we are too busy to have power. We have a great deal of activity, but we accomplish little; many services but few conversions.
Do not just begin to pray and pray a little while and throw up your hands and quit; but pray and pray and pray until God bends the heavens and comes down.