Today's passage covers the sanctification of the firstborn; the Exodus from Egypt; the parting (and re-closing) of the Red Sea; a song of praise to the Lord by the Hebrews; and the first of their wanderings.
It has been remarked by better scholars than I that the God of the Old Testament often acts differently than the God of the New Testament. We have seen instances of God's anger before, even instances where God has killed thousands or millions of people. I point your attention, for example, to the great flood (Gen. 6-8), the destruction of Sodom and Gomorrah (Gen. 19), and of course the 10 plagues on the Egyptians (Ex. 7-11). In today's readings we see another such instance: God kills all the Egyptians who pursued the Hebrews into the Red Sea.
We read that Pharaoh brought six hundred of his best chariots, all the other chariots in Egypt, and officers for all of them. (Ex. 14:7) Remember that he was trying to catch a host of six hundred thousand men, plus their women, children, and belongings. His pursuing army would undoubtedly have been quite large as well. Further, they would have been far better armed than the Hebrews, who until recently had been enslaved.
Sure enough, they do catch the Hebrews in good time. But they are not allowed to slaughter them. God, in the form of a pillar of cloud and fire, places himself between the Israelite camp and the Egyptian one, so that the Egyptians could not approach their target. (Ex. 14:19-20) Meanwhile, Moses raised his staff and God parted the sea, allowing the Israelites to cross on dry land. (Ex. 14:21-22)
The Egyptians, seeing what had happened, pursue them. But God was never one for half-measures. When the Egyptians are within the now-dry seabed, God casts their army into confusion, breaks the chariot wheels from their chariots, and routs the Egyptians. (Ex. 14:23-25) The Egyptians, fully seeing the power of God, attempt to flee. But at this very moment, God commands Moses to re-close the waters and drown them. The Egyptians cannot flee fast enough, given their broken chariots. Moses does as he is commanded, and every single Egyptian who pursued the Israelites dies. (Ex. 14:26-28)
This is clearly not the action of a God who says, "turn the other cheek." (Matt. 5; Lk. 6) This is a God who is full-set on vengeance, retribution, and war. Indeed, as the story progresses, the Hebrews must face and fight a number of nations who had settled in Canaan during the intervening 400 years. The God they follow is a war god, enabling them to conquer their enemies and emerge victorious.
The Hebrews are clearly aware of the nature of their God. In Ex. 15, they sing a song of praise to God for the feat he had just accomplished. (Ex. 15:1-18) This song contains phrases such as:
(3) The LORD is a warrior;
the LORD is his name.
(4) Pharaoh's chariots and his army
he has hurled into the sea.
The best of Pharaoh's officers
are drowned in the Red Sea.
(5) The deep waters have covered them;
they sank to the depths like a stone.
(6) Your right hand, O LORD,
was majestic in power.
Your right hand, O LORD,
shattered the enemy. (Ex. 15:3-6; NIV)
The Hebrews here are clearly exalting the God who slaughtered their enemies. Furthermore, they are confident that God will continue to slay their enemies:
(14) The nations will hear and tremble;
anguish will grip the people of Philistia. (KJV: Palestina)
(15) The chiefs of Edom will be terrified;
the leaders of Moab will be seized with trembling,
the people of Canaan will melt away;
(16) terror and dread will fall upon them.
By the power of your arm
they will be as still as a stone--
until your people pass by, O LORD,
until the people you bought pass by. (Ex. 15:14-16, NIV)
This is a reference to the future wars that are imminent. The Hebrews know that there are other nations living in the land of their forefathers. If they want to reclaim those lands, they will need to do so by force. They are confident that their God will lead them in victory against them, just as he did against the Egyptians.
We should note that it is not just the men who sing these war songs. The women, led by Miriam, Moses' sister, dance and sing accompanied by tambourines. (Ex. 15:20-21; "timbrels" in the KJV) The women, as well as the men, rejoice in the slaughter of the Egyptians.
All this behaviour seems a far cry from Jesus, who issued such lessons as "whosoever shall smite thee on thy right cheek, turn to him the other also." (Matt. 5:39, KJV; Lk. 6:29) Jesus spoke of forgiveness, the Old Testament God about vengeance. The differences are blatant.
I do not mean, by this discussion, to claim that one portrayal of God is better than the other. I do not even mean to say that they are separate gods. If you believe in the Christian cosmology, God is the same in both the Old Testament and the New. I do say, however, that he is portrayed differently in the two narratives. This might have been deliberate: God may merely have revealed himself in a way appropriate to the time. When the Jews were underdogs in Egypt, God was a liberator. When they charged into battle to reclaim Canaan, he was a war god. When they settled in that land, he was a judge and a law-giver. When, much later, they were in a Roman culture favourable to mystery cults, he emerged in a persona appropriate to that. There is no inherent contradiction here. Being monotheistic, the Hebrew and Christian God needed to encompass the functions of many separate polytheistic gods in a pagan pantheon.
All I'm saying is that the differences in behaviour are explicit and striking.