The basis of Exodus is to show God's claim to his people, and set up an alliance with Israel and the laws. Exodus sets up a legal system that should be followed through the chapters, while telling the story of how Israelites were delivered from slavery in Egypt. This was done with God's covenant with Israel, the 10 Commandments at Sinai, and the rebellion of his people in the golden calf incident that led their obedience in building the tabernacle that was originally requested, to have God accompany Israel to the promise land.
Exodus 14 tells about when the Israelites are fearful of the approaching Egyptians. "In great fear the Israelites cried out to the Lord" (14:10). Moses has to tell the Israelites to go back and set up camp and place themselves between the sea and the Egyptians. Moses said to the people, "Do not be afraid, stand firm, and see the deliverance that the lord will accomplish for you today; for the Egyptians whom you see today you shall never see again. The Lord will fight for you, and you have only to keep still" (14:13-14). This was God's way to show his people how powerful he is and all they need to do is have faith in him. This is written to show the readers to stand up and face any kind of fear and as long as you're doing it in God's name he will protect you. This could also been seen as encouraging to be faithful and follow God's word. .
The Lord saved Israel by having Moses part the sea for his people to walk across the dry land. Then when the Egyptians go to follow he has Moses put his hand back over the sea so it can swallow up all the Egyptians and their chariots. "Then the Lord said to Moses, Stretch out your hand over the sea, so that they water may come back upon the Egyptians, upon their chariots and chariot drivers" (14:26). They were able to see the entire Egyptian army, dead on the shore. "So the people feared the Lord and believed in the Lord and in his servant Moses" (14:31).
