See you then!
Many people that read about the blood on the doorpost don't understand what God was doing and why He did it.
God made a law about the "first born" that must be followed. When a firstborn male was born, he must be redeemed with a ritually clean animal such as a lamb. If a donkey was born, you must redeem him with a lamb's death if you wanted to keep him. If you didn't need the donkey, you must break the neck of the donkey. God deemed a male child as an unclean animal, so every Jew had to redeem their firstborn with a lamb. God was demonstrating that He wanted to redeem the nation of Israel's firstborn with the blood of a lamb.
There was also a law for a "census tax" in Israel. You could pay the tax by donating a half shekel of silver to the Temple. That is why David counted his troops and 70,000 died that day because he didn't pay the tax. Silver symbolizes blood in Scripture so the whole Tabernacle was suspended on blocks of silver to keep it off the ground. By accepting the sacrifice of Jesus, we are redeemed by the blood of the Lamb just as Israel was redeemed and saved from the Death Angel. God always follows the law He wrote.
To be redeemed means blood must be shed to save the redeemed object. Even the land had to be redeemed in Israel.
The firstborn of Egypt had to die for the firstborn of Israel. We must die in the flesh to be born again in the Spirit to be redeemed to God. Jesus was willing to shed His blood so we could be kept alive by God because we are unclean.