When reviewing Parashat BeShallach, a fascinating Pasuk jumps out as ripe for interpretation. Right before B’nei Yisrael launch into the Shirah, the Torah tells us “VaYir’u HaAm Et Hashem, VaYa’aminu BaHashem UVMoshe Avdo,” “The nation feared God, and they believed in God and in Moshe His servant (Shemot 14:31). Even at a simple level, to fully understand this Pasuk is tricky. What does it mean that B’nei Yisrael now “believe in God and in Moshe”? First of all, B’nei Yisrael just bore witness to months upon months of miraculous, nature-defying plagues—does the one miracle at Yam Suf really make that great of a difference to their belief? Additionally, the Torah already established within the earlier episode of Moshe coming to the people with God’s message that “VaYa’amein HaAm,” “the nation believed (4:31). Apparently, a basic belief in the legitimacy of God and his messenger Moshe was already present. What, then, is the new Emunah generated at Keri’at Yam Suf?
Various approaches to this question can be found amongst the commentators. Targum Onkelos, for example, offers an explanation in his translation of the Pasuk: “VeHeiminu BeMeimra DeHashem UViNvi’ut Moshe Avdeih,” “They believed in the word of God and in the prophecy of Moshe His servant (14:31). With his additions, Onkelos provides a simple way of answering our question: B’nei Yisrael, after finally seeing all the words of God come to fruition with the destruction of the Egyptians, now believed in the truth of God’s word, and, by extension, the method through which those words had been conveyed to them (i.e. the prophecy of Moshe).
I, however, would like to suggest a different answer, one which is rooted in the mindset of B’nei Yisrael prior to Keri’at Yam Suf.
Before the whole episode of Yezi’at Mitzrayim, B’nei Yisrael were slaves for over 200 years—generations upon generations were forced to look toward the Egyptians as their masters. In this sense, B’nei Yisrael developed a deep-rooted mentality of man as the master, and they could not conceptualize the existence of any other type of master-servant relationship. Even though they lived through the Makkot, when the heat is on and the Egyptians come chasing, B’nei Yisrael immediately revert back to their mentality as slaves. They come to Moshe in a panic and exclaim, “HaLo Zeh HaDavar Asher Dibarnu Eilecha BeMitzrayim Leimor, ‘Chadal Mimenu VeNa’avdah Et Mitzrayim’?’” “Isn't this the thing about which we spoke to you in Egypt, ‘Leave us alone, and we will serve the Egyptians’?” (14:12). At their core, B’nei Yisrael understand only that they are slaves to the Egyptians; when pressed, that is what they revert to.
Moshe Rabbeinu’s response to their outcry is critical: “VaYomer Moshe El HaAm, ‘Al Tira’u; Hityatzevu UR’u Et Yeshua’at Hashem … Hashem Yilacheim Lachem, VeAtem Tacharishun,” “Moshe said to the people, ‘Don't be afraid! Stand firm and see God’s salvation … God will fight for you, and you shall remain silent’” (14:13-14). Moshe remains unflinching; he impresses upon the people a firm belief that God will bring aid, even if by all laws of man, none should come. While B’nei Yisrael’s fear indicates that they are still servants of man, Moshe Rabbeinu’s steadfast faith shows him to be a true servant of God.
And what happens? The Emunah that springs from Moshe’s devotion is perfectly carried out: B’nei Yisrael walk through the Yam Suf on dry land, while the waters crash down behind them onto the Egyptians.
Perhaps, then, we can understand the Emunah that B’nei Yisrael develop at the Keri’at Yam Suf. It is not some general belief or faith in the word of God; rather, what B’nei Yisrael develop is Emunah in the conceptual model of man-God relationship known as “Eved Hashem.” The events surrounding Keri’at Yam Suf, specifically Moshe’s steadfast devotion to God, open the eyes of B’nei Yisrael to a state of being that was totally foreign to them, namely, that of a servant to God. The Jews were totally immersed in physical slavery, where their master was always a human, and they could then only understand the dominance of a mortal power. When their physically-dominant Egyptians masters come chasing after them, they ultimately succumb to the fear and to their instinctive understanding of slavery. Yet Moshe shows them a new way to live: putting faith not in a physical master but rather in some higher and greater Adon. I think this interpretation fits the words of the Pasuk, “Vaya’aminu … BeMoshe Avdo” (14:31)—B’nei Yisrael come to believe in the lifestyle of Moshe, in the idea that one can live as “Avdo” to God.
This approach, albeit unorthodox, to B’nei Yisrael’s realization at the Yam can then provide a better understanding of some surrounding details.
First of all, I think it clarifies a famous Midrash regarding Kriat Yam Suf: “Ra’atah Shifchah Al HaYam Mah SheLo Ra’u HaNevi’im,” “A maidservant saw at the sea what all the prophets did not” (quoted by Rashi 15:2 s.v. Zeh Keili). Perhaps, in light of my approach, the choice of the Midrash to highlight the perception of the Shifchah is core to its meaning: even those most “enslaved” at Keri’at Yam Suf (i.e. the Shifchah) achieve profound insight into God, as everyone who bears witness to the events fundamentally understands that the only true servant-master relationship is one of man-God, not man-man.
Second, I think my approach can explain a detail about the route that B’nei Yisrael take through the Midbar prior to Keri’at Yam Suf. The very first Pasuk of the Parashah describes Hashem’s reasoning for not taking B’nei Yisrael along the Derech Eretz Pelishtim: “Amar Elokim, ‘Pen Yinacheim HaAm BiR’otam Milchamah VeShavu Mitzraymah,” “God said, ‘Lest the people reconsider when they see war and return to Egypt’” (13:17). Yet, almost immediately after Keri’at Yam Suf, when B’nei Yisrael begin on their supposedly war-free path, they are attacked by Amalek and forced into war! If Hashem’s concern is war, why does He lead B’nei Yisrael towards the Yam Suf and war with Amalek?
I think my approach provides a convincing response: Hashem has no qualms about leading B’nei Yisrael towards Amalek because B’nei Yisrael will first experience Keri’at Yam Suf, the experience that makes them believe in the notion of an “Eved Hashem.” So, when Amalek attacks, all Moshe has to do is raise his arms heavensward, and “VaY’hi Yadav Emunah,” “his hands were like a faith” (17:12). Had B’nei Yisrael gone Derech Eretz Pelishitm, they would still only know servitude to man, and once they saw that their physical strength could not overpower the enemy, they would have fled. But now that B’nei Yisrael have gone through the Yam Suf, have seen Moshe act as the paragon of an Eved Hashem, they need only to look to him to be reminded of the reality that they exist not as Ovdei Adam but as Ovdei Elokim and that it is their Tefillot that will win them the war, not any human strength.
Ultimately, I think this lesson is one even for the modern day. Though not slaves, we still remain servants to man and materialism, in one form or another. It is our duty, then, to truly recognize the truth in serving only God—to be Ma’amin BaHashem UVMoshe Avdo.
 Though Bnei Yisrael do initially cry out to God (see 14:10), it seems that terror eventually overcomes them, and they approach Moshe in a frenzy in the very next Pasuk.
 More traditional approaches to this question can be found within the commentators; see, for example, Ramban