We mention the splitting of the sea every day in the morning Shacharis and by Maariv by night before Shemone Esrei.
However there is an interesting difference. In the morning prayers we say "and the Yam suf, You (Hashem) split and the Egyptians were sunk and the "Yedidim" - the dear ones, You crossed over the water..... For this the beloved ones - "Ahuvim" praise you and exalt Hashem, and the dear ones give song, praise to the King who is our G-d forever.
At night we say that Hashem crossed his children the split parts of the Yam suf....and His children saw His greatness and they praised His name.
Why is it that by day we speak about the beloved ones and the dear ones, whereas by night we just mention Klal Yisrael as Hashem's children?
When Klal Yisrael came to the Yam Suf there was panic. The Egyptians were coming from behind them and the water was in front of them. There was nowhere to escape. The Midrash tells that some Jews were praying, some wanted to go back to Mitzrayim and some wanted to fight. There was pandemonium.
There were the Jews who lived with Emunah - faith, and had trust in Hashem. For them even such a dangerous time was clear like daylight that Hashem is running the world. They are the Ahuvim - the beloved ones, and Yedidim - the dear ones.
Those that were scared and wanted to go back, they were living in the darkness, lacking true faith and trust in Hashem. But even so a child remains a child! "Banim atem lashem Elokeichem" - we are all children of Hashem.
Even though they were lacking trust but Hashem still crossed His children over the Yam Suf. They may not be beloved at that moment but they were still His children.
So no matter how weak we are in our Emunah, no matter how poor our Shemiras Hamitzvos are, but Hashem is our Father and we are his children, FOREVER!
Our aim is to strengthen ourselves bit by bit, more and more till we reach the level of being called Ahuvim and Yedidim.
Pharaoh's Plan and Hashem's Response
Pharaoh wanted to outsmart the Jews. Pharaoh knew that Hashem punishes a person 'Midda keneged midda' - the punishment is connected and similar to the action of the sin. He made a decree that all Jewish children should be thrown into the water. He knew that Hashem promised never to bring another Mabul - flood to the world. Rashi writes that he made a mistake, because Hashem's promise was for the whole world but could still bring a flood on a single country. Furthermore Pharaoh never understood that Hashem never needed to bring the flood to him, Hashem just caused them all to willingly enter the water and meet their end. That never entered his mind.
A wealthy Jew came to the Chafetz Chaim and asked him, "it says that Hashem can make a person become wealthy or poor in a split second. I don't see how Hashem can do that to me. I have so much property and land, so many factories, so many investments in stocks and banks, May Hashem look after me. But in one second?"
The Chafetz Chaim smiled and replied, "you claim that Hashem can't take everything away in a moment? Maybe. But he can take you away from your wealth in a second!"
The man paled!
However we must understand. Pharaoh and the Egyptians chased after the Jews and entered the Yam Suf. They saw the water split into twelve parts for each tribe. The floor was smooth, there was an ice roof. Was Pharaoh so stupid? Did he think it was made for him? After ten plagues was he still so blinded?
The Ramban explains that Hashem made very powerful winds the night of the splitting of the sea, so much so, that the Egyptians thought that it was that what made the sea split. They never took notice about all the partitions in the water, they were blinded by their hate.
The Parable of the Alcoholic
There was an alcoholic who was so addicted that he caused terrible embarrassment to his family and friends. He would collapse in the middle of the street and go to sleep. It was impossible to stop him. His family got together and decided that they couldn't stop him drinking completely, but must find some way out. They forced him to promise that he wouldn't drink alone, only in company. That way he would be limited to when he could drink. Also he would have someone looking after him keeping track of how much he drinks and making sure he gets home safely.
He was determined to keep to his promise and was waiting for someone to share a drink. Everyone was too busy to give him time.
He was getting desperate, but kept control. He said to himself that although he promised not to drink alone, he would prepare everything up front so when he would finally have some company everything will be completely ready.
He brought a bottle of whiskey and two glasses to the table. But no one came.
He decided to shorten his wait. He filled both glasses till the top. The aroma filled the room. But he promised and a promise is a promise! He couldn't control himself and no one was showing up.
Suddenly his eyes lit up. A fly was buzzing around the room and stopped on the tip of the full glass.
Without thinking anymore he shouted "Lechaim" and drank the glass. He turned to the fly and said, "by the time you start drinking, I will have finished the whole bottle!"
In the end, he sadly had to drink the fly's glass too. Did he break his promise? But when so desperate to drink even a fly can be company. So what can we expect from Pharaoh? He was so blinded by the money and wealth, he and his country lost, can we blame him for being so blind and marching his whole army to their death!