This last Sunday I preached from Exodus 6. The one point for the sermon was: We are to trust in God's promises not in our own inadequacies. Exodus 6 follows the first time Moses went to Pharaoh. It was a terrible failure. Pharaoh made the work load of the Israelite slaves worse than it already was.
God then gives Moses some amazing promises which Moses then shares with the Israelite people. The Israelites do not believe Moses and get discouraged.
God then tells Moses to go to Pharaoh again. But Moses says "If my own people will not listen to me, why would Pharaoh, besides, I speak with faltering lips."
Moses failed once even after God told him to go to Pharaoh, then Moses fails at least 10 more times before Pharaoh lets the people go. Even when God calls us to a mission, failure is an option. The key is not to focus on what we can't do, but what God can do. We are to live in His promises, not in our in inadequacies.
May you trust in God, even when your circumstances appear to be a failure.