10 Then the LORD said to Moses, 11 “Go, tell Pharaoh king of Egypt to let the Israelites go out of his country.”12 But Moses said to the LORD, “If the Israelites will not listen to me, why would Pharaoh listen to me, since I speak with faltering lips?”(New International Version)
Moses did obey God, however, and what a difference it made!
When the chances for success appear slim, remember that anyone can obey God when the task is easy and everyone is behind it. Only those with persistent faith can obey when the task seems impossible.