Defeat the giant in my life

I Samuel 17:38-58
David is not used to ware tunic to fight, he is used to use sling and stone as weapon.
David said " All those gather here will know that it is not by the sword or spear that the Load saves; for battle is the Load's , and he will give all of you into our hands.
David said to the Philistine " You come against me with sword and spear and javelin, but I come against you in the name of the Load Almighty.
Why?
David don't afraid for he knows God is with him "be used to" is a gift from the Load, it will be useful when use for the Load.
Battle is the Load's, how wonderful it is, I don't afraid battle, I need to pray and do my responsibility- listen to the Load.
David played harp for Saul for many times when he needed, Saul didn't know his family. Saul didn't care about who served him. David was nobody before this battle.
How?
Do not despise my gift, it might be a very little gift, it could be used for the Load when we rely on the Load.
Come against the giant in our life need the help of the Load, let God be my Load he can conquer the battle, defeat the giant.