2Cor 10:3-5, 4 For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds
David in 1Sam 17 faced a great enemy of God’s people. His age, size and weapon were rendered inferior in terms of who he was facing unless everything about him became might in God. The Bible describes Goliath as a giant, trained and well prepared for battle. Despite it all, David had a battle plan, he spoke with conviction of the testimony of God and that I believe demoralized Goliath. The stone merely finished the job or put a period at the end of a sentence.
If we doubt the credibility (testimony) of the Word, its authority and its sufficiency, we have lost the battle. “…The appointed means, however feeble they appear to some, will be mighty through God. And the preaching of the cross, by men of faith and prayer, has always been fatal to idolatry, impiety, and wickedness” (Matthew Henry). Moses’ staff he used to shepherd the sheep in the wilderness God used it to lead His sheep out of Egypt, it was referred to to as the “Staff of God” (Exo 4:20). In Moses’ hand it was inferior, in Moses’ hand through God it was mighty. God’s word is the greatest staff (weapon) in our hands rendered powerful through prayers.