You know with all your heart and soul that not one of the good promises the LORD your God gave you has failed. Every promise has been fulfilled; not one has failed. Joshua 23:14
We would do good to take this verse to heart ourselves as David did in 1 Samuel 17:33-37. David volunteers to go and fight the giant Philistine that no one else will dare face. The king Saul replies to Davids brave offer with “You are not able… you are only a boy…” (vs. 33) All of us have probably heard or felt this way at one point or another… “You are/I am not able to- (fill in the blank). You are/I am only a- or not enough- (fill in the blank).” So easy to believe the hope deflating words spoken by the world or even ourselves. Not David! He could easily have slunk back in despair or self pity but David responds as we should if we too believe Joshua 23:14. God is faithful!
David immediately begins to recount to king Saul all the ways God has already showed up in his life and won battle after impossible battle for him! He tells Saul this battle against the Philistine will be no different in that his God will show up! David has God-confidence rather than self-confidence. He knew his God would not be mocked and a man reaps what he sows (Gal. 6:7) and this mighty Philistine had defied the armies of the living God.
So do not let what the world says of you or your circumstances be the last say… the Lord looks at the heart and sees what no man can; let His word and His alone be the final say, and He says what He starts in a life, He will finish and nothing is impossible for Him! Remember how God has already showed up faithful in your life like David did and allow that to fuel the fire of belief in a faithful God who can be trusted again. He doesn’t change like shifting shadows, He is the same yesterday, today and tomorrow! Similar to how David responded in vs. 37 we can respond to the enemy (even if the enemy is our self); The LORD who delivered me from (you fill in the blank) and the (you fill it in) will deliver me from (you fill it in). The king then said to David, “Go, and the Lord be with you.” (And He certainly was if you know the end of the story, just as He will faithfully be with you– till the very end of the age!!)
Independent Read: Matthew 28:20, James 1:17, Hebrews 13:8, 1 Samuel 17:37, Philippians 1:6, Matthew 19:26, 1 Samuel 16:7