"By faith they passed through the Red Sea as by dry land: which the Egyptians assaying to do were drowned," (Hebrews 11:29 KJV)
"As Pharaoh approached, the people of Israel looked up and panicked when they saw the Egyptians overtaking them. They cried out to the LORD, and they said to Moses, "Why did you bring us out here to die in the wilderness? Weren't there enough graves for us in Egypt? What have you done to us? Why did you make us leave Egypt? Didn't we tell you this would happen while we were still in Egypt? We said, 'Leave us alone! Let us be slaves to the Egyptians. It's better to be a slave in Egypt than a corpse in the wilderness!'" But Moses told the people, "Don't be afraid. Just stand still and watch the LORD rescue you today. The Egyptians you see today will never be seen again. The LORD himself will fight for you. Just stay calm."" (Exodus 14:10-14 NLT)
Somebody once said, "Act as if you have faith!" This idea is most likely taken from something Jesus said about moving mountains. (Matthew 21:21-22) The point being, that Moses really didn't know what God was going to do, only that God wasn't going to let His people be killed by the Egyptians, because the plan was to get them back to the land where they belonged.
Much as Paul was not concerned over the poisonous snakebite, because he knew that he had to go to Rome, because God already told him it would happen. Moses might not have known what God would do, but he knew that one way or another, He would take care of His people and destroy the Egyptian army.
The whole point to this title, "Leap of Faith," is not based upon the faith of the people, because they had no faith, but only complained around every corner. Whenever there was anything to complain about, they would say, "Why did you take us out here to die!" It was Moses that had faith enough to know that God was able to do what was needed; no matter what it might have been, God could do anything!
As for the statement, "Act as if you have faith!", this is not really something that is played out, as if we are pretending to have faith that God will do something, but that we trust that God will do whatever he has promised, no matter what! We might not know how He will do it, and we certainly don't know when; but we can act as if He is doing it, by the faith that He is good and faithful...
"Then the LORD said to Moses, "Why are you crying out to me? Tell the people to get moving! Pick up your staff and raise your hand over the sea. Divide the water so the Israelites can walk through the middle of the sea on dry ground. And I will harden the hearts of the Egyptians, and they will charge in after the Israelites. My great glory will be displayed through Pharaoh and his troops, his chariots, and his charioteers. When my glory is displayed through them, all Egypt will see my glory and know that I am the LORD!"" (Exodus 14:15-18 NLT)