They weigh slavery against death.
Pharaoh's chariots come up behind the camp. The sea is in front. The people see the army, are terrified, and cry out to the LORD. Then they turn on Moses: were there no graves in Egypt, that you brought us here to die?
The reader knows the camp by the sea was a lure to draw Pharaoh out. Whether Moses told the people, the chapter never shows. From where they stand, their terror makes sense. And look at what they compare: not slavery against freedom, but serving Egypt against dying in the wilderness (14:12).
The common reading is that fear sent them longing for Egypt, and the order of events makes that fair. One way to hear it: with the army in sight, the unknown future has only one picture left, death. Slavery was hard, but they had survived it. When you imagine leaving something familiar, does the other side look like a different life, or like dying in the wilderness?
Egypt reaches back too.
When word comes that the people have fled, Pharaoh and his servants ask why they let Israel go from serving them (14:5). A few verses later the people say it would have been better to serve the Egyptians (14:12). In the King James wording, 'serve' sits on both sides. Read together, captor and captive both seem to reach back for the old arrangement.
The chapter also says the LORD hardens Pharaoh's heart (14:4, 8) and the Egyptians' hearts (14:17). So the chase comes from Pharaoh's own stated regret and also from a hardening the chapter credits to God. Jewish and Christian readers have long argued over how those fit: God overriding Pharaoh's will, or confirming a choice he had already made. The chapter holds both.
Stand still, then go forward.
Moses is blamed for a plan that was not his. He does not blame back. He tells them: do not fear, stand firm, watch what the LORD will do today, be still. If you lead people through a change, that answer is worth studying.
Then the next word from God turns: tell the people to go forward, and stretch your rod over the sea (14:15-16). The chapter sets the two side by side. Stop running. Then move.
The sea divides before anyone steps in. All night an east wind drives it back while the cloud stands between the camps. Then Israel walks through on dry ground, and the Egyptian army follows them in. Hope in this chapter has feet: it moves while the army is still in pursuit.
Belief comes after they see.
The only report of belief comes at the end. Israel sees the Egyptians dead on the shore and sees the great work the LORD did. Then the people fear the LORD and believe him and his servant Moses (14:30-31). Moses's earlier reassurance is not reported as changing anyone's mind, or as failing to.
Fear language opens and closes the episode. The people are 'sore afraid' of the army (14:10). At the end they 'feared the LORD' (14:31). The fear has a new object.
The usual reading is that their trust faltered at the sea and came back when they saw the rescue. That fits the order of events, though they did cry out to the LORD at the worst moment. Maybe you are waiting to feel sure before you move. Here, the walking comes before the word 'believed.'
