First and foremost, the object of our faith is Jesus. We know and believe in Jesus and what he has done for us. And along with that trust, comes trust in all other promises that he has made in his Word. It’s not our faith that is strong. It is the object of our faith that is strong, and he is the One who saves! Maybe “strong” or “weak” aren’t the best descriptors of faith. We are always weak. But God is always strong! On our own, we are nothing, and wouldn’t have faith at all. But by God’s grace we believe, we have faith. It’s not a question of “how much”, therefore, but “in whom” we believe.
They say, “Repetition is the mother of all learning,” which is exactly what God does with Joshua – repeats the promise of his protection again and again. God knows that by human standards Joshua had every right to be shaking in his boots, but because God is in control of all and every situation, he wanted Joshua to know that he had nothing to fear, whatsoever, but had every right to be “strong and courageous.” What was true of Joshua is also true of you and me, no matter the circumstance or trial that confronts us.