Joseph and his brothers marry and have children and their children have children until they become a great nation: Israel. So great have their numbers become in Egypt that the king of Egypt enslaves them in forced labor enforced by brutality and oppression.
God sees the injustice his people have to endure and has compassion on them. He attempts to convince the king of Egypt to let the people of Israel go free through a series of judgments: plagues of frogs, gnats, flies, and painful boils. God’s climactic judgment of Egypt is the angel of death sent to kill the firstborn in every household. But before God unleashes this, he instructs the people of Israel to take a lamb, sacrifice it, and put its blood on the door frames of their homes. That night, when the angel of death swept through Egypt and spotted the blood on a door frame, he passed over that household sparing the firstborn.
Jesus is the true and better lamb. Those who hide behind his blood will be spared. Are you covered by the blood of the lamb?
The Bible is not a collection of isolated stories, but a single, unified story ultimately about Jesus Christ.