David said to Ahimelech, "Now is there not a spear or a sword on hand? For I brought neither my sword nor my weapons with me, because the king's matter was urgent."
1 Samuel 21:8-10
David defeated Goliath, the giant from Gath without a weapon. Now because of fear or lack of faith David runs to Gath with the weapon of a Gittite (man from Gath is a Gittite), and he is utterly impotent.
Why do believers trade the armor of God for the weapons of the defeated enemies of God? You can't win a war against the flesh with weapons of flesh. The flesh is already defeated. Its weapons have been proved to be of no use for God.
If you are fighting with five stones that are exactly like five thousand other stones from the river, your trust is in God, and you win. When you are fighting with the best sword in the world, the sword with no equal, your trust in the sword; and you lose.
For though we walk in the flesh, we do not war according to the flesh,
2 Corinthians 10:3-4
For me to live is Christ.