“Let it go, let it go. Can't hold it back anymore.” Having lived so long in hiding with such tight control over her power Elsa’s song was an emotional burst of relief as she finally "let it go". Feeling herself freed from the constraints by her distance from the city she unleashed her strength high in the mountain. Besides being an immensely popular movie, song and character it was a beautiful portrayal of the pain of loss and fear that traps far too many people in chains of their own making; though sometimes those chains are started by others (such as her parents in the movie).
Gideon, the reluctant warrior, needed to “let it go” because he was living in chains of his own making due to his lack of trust in God. Of course those chains were started by his parents and others who had rejected God for Baal worship and become oppressed by the Midianites. So when God told him it was time to “let it go” it shouldn't surprise us that his sense of fear kept holding him back. First he had to see the angel’s miracle (Judges 6:21), then he needed to see the miracle of the fleece (Judges 6:36-40) and before he could “let it go” and lead the 300 against the Midianite host he needed one more reassurance.
Previously God’s grace was shown by His gentle response to Gideon’s distrust, but God proposed the third test to Gideon because he needed further proof that victory was imminent. He had Gideon sneak down into the Midian camp and hear a soldier talking about God giving them into Gideon’s hand (Judges 7:9-14). After hearing that Gideon was prepared to “let it go” and follow God’s command (Judges 7:15). How many of us need to let go of the fear that binds us and serve God with our whole heart?