By strength no man shall prevail. 

Then David said to the Philistine, “You come to me with a sword, with a spear, and with a javelin. But I come to you in the name of the Lord of hosts, the God of the armies of Israel, whom you have defied.” … Then David put his hand in his bag and took out a stone; and he slung it … So David prevailed over the Philistine with a sling and a stone.No king is saved by the multitude of an army; a mighty man is not delivered by great strength … Behold, the eye of the Lord is on those who fear Him, on those who hope in His mercy. § Both riches and honor come from You, and You reign over all. In Your hand is power and might; in Your hand it is to make great and to give strength to all.I will rather boast in my infirmities, that the power of Christ may rest upon me. Therefore I take pleasure in infirmities, in reproaches, in needs, in persecutions, in distresses, for Christ’s sake. For when I am weak, then I am strong.