Actually, the Red Sea was divided into twelve parts, allowing each tribe to walk though separately. The Sfas Emes explains that Hashem did this to teach them that each individual tribe has its own singular mission and, thus, deserves the miracle of the Splitting of the Red Sea for its own sake. In Sefer Tehillim 136:13, David Hamelech records the miracle, L’Gozeir Yam Suf ligzarim, “Who splits/divides the Red Sea into parts.” Surprisingly, the pasuk is written in the present tense, as if Hashem continually splits the Red Sea. (Veritably, the commentators translate it in the past tense, but l’gozeir is present tense). This begs elucidation, since obviously, the sea reverted back to its original position.
In an earlier pasuk (136:7), David Hamelech writes, L’Osei orim gedolim, “Who makes great lights.” In his Nefesh HaChaim, Horav Chaim Volozhiner, zl, explains that Hashem constantly renews the act of creating the world. He did not create the world and then leave it on auto pilot. Every second, He recreates the world. This might explain the luminaries, but this explanation will not provide a solution for the present tense concerning the splitting of the Red Sea.
Horav Yisrael Eliyahu Weintraub, zl (quoted by Horav Shlomo Levenstein in the name of Horav Avraham Brode), explains this based upon an incident that occurred with Horav Mordechai Pogremansky, zl.
Rav Pogremansky was a singular gadol who had earned the esteem of the greatest Torah giants of the previous generation. His brilliance and unparalleled erudition were only matched by his total devotion and commitment to Torah and mitzvos. He passed away in Switzerland one year after he married. His body was brought to Eretz Yisrael where he is buried in the cemetery in Bnei Brak. Following his funeral, which was attended by many gedolim, the Chazon Ish stood over his freshly sealed grave and wept bitterly until the ground became wet with his tears.
During his illness, which began shortly after his marriage, he lay in a hospital in France wracked with pain. Constantly at his side was his close student Rav Yosef Roth. One time, when Rav Mottel, as he was endearingly called, thought no one was with him in the room, Rav Roth heard him plead, “Ribono Shel Olam, without mercy! Without mercy! Give me what I deserve! I want to achieve a pinnacle of purity. I beg no mercy!”
Now, for the dvar Torah. Rav Weintraub related that when he was together with Rav Mottel in the Kovno Ghetto (during World War II), Rav Mottel once approached two bachurim, yeshivah students, and asked, “What do you think Hashem wants of us?” “Is that the question now?” one of them responded. “Now, we are starving to death. The question is where will we obtain food? Who is thinking about what Hashem wants of us?”
Rav Mottel was acutely aware of the source of their response. They were all starving. He had an important message, however, to convey to them via his question. (This is how he lived. He was a deep thinker, and, as a result, his mind was in a different realm of activity than those around him.) “Let me explain my question to you,” he began. “How valuable is the blood of a Jew?” he asked. Their immediate response was, “Absolutely nothing.” Jewish blood during the war in the Kovno ghetto, where they were exterminating Jews right and left, had no significance and, hence, no value.
“What would happen if someone came along now and murdered a Jew? Would he be found guilty and sentenced as a murderer?” he asked. “No,” was their response. “Let me ask you,” and he pointed to a group of Nazis who were standing a few hundred feet away. “Those Nazis, do you think they want to kill Jews – or not?” Their reply was to be expected. “Certainly. They know that there are no consequences. Jewish blood is worthless. Sure, they want to kill us.”
“Now, listen to what you are saying,” Rav Mottel said (this time with emotion). “They have no qualms about murdering us. In fact, they probably want to. No one will arrest them, because no one cares. Jewish blood is cheap. In fact, if they would commit murder, no one would either question them or care. It would be absolutely nothing. So, let me ask you: Why do they not kill us? There can be only one reason: Hashem does not permit them to do so. I have no idea what will occur in sixty seconds, but right now I know that Hashem wants us to live. The greatest proof of this verity is that we are still alive! Why does Hashem want us alive? Obviously, He expects something of us. That is my original question to you: ‘What does Hashem want of us?’”
Rav Weintraub continued: “At times, the normal situation/climate in the world is to live. There are times (such as during war, famine, etc.) that the normal circumstance is death. People are dying all over. Yet, despite the climate of death all over, some people are not dying. Why? It is because Hashem wants them to live. He expects something of them. The question that confronts the ‘survivors’ is: ‘What does Hashem want of us?’ Why is He changing what seems to be the normal climate of death and allowing us to live?
“What is the natural/normal matzav, situation, in this world? Apparently, one would posit that it is life. That is what we might assume.” Rav Weintraub explained, “Chazal, however, do not agree. The Midrash (Tanna Dvei Eliyahu Zuta 5) relates that everyday Malachei Chabalah, angels whose mission it is to harm, come before Hashem prepared to cause great harm to the world. If it would not be for the shuls and batei midrashos where Torah scholars are immersed in prayer and Torah study, they would destroy the world. In other words, the normal situation in the world is not life, but death. At any given time the world could be destroyed. Why is it not? Because Hashem refrains from doing so as a reward to those who devote themselves to Torah study.
At the Red Sea, Hashem wrought a singular miracle that went against the natural order of the world. Naturally, when a person plunges into the sea, he drowns. The Jewish People entered and miraculously lived. In our everyday world, Hashem is constantly saving us from what normally would occur if the Malachei Chabalah had their way. Thus, our very existence, our everyday ‘normal’ life, is actually not so normal. As a result, the pasuk is written in present tense. Every moment of our existence Hashem continually acts against the forces of ‘normalcy,’ just as He did when He split the Red Sea. As He went against nature, transforming it to serve His people, allowing them to pass safely through, so, too, does He constantly fend off those who would do us harm. All in the z’chus, merit, of the Torah that is studied. We must always ask ourselves, ‘What does Hashem want of me now?’”