In the Passover ceremony, the blood of lambs was collected in basins. Once the blood was transferred from the basins to the Israelites’ dwelling places, they were safe, on one condition: they had to stay inside their houses.
This truth is very important: the blood protects only the obedient. You are safe while you obey. Let’s look at 1 Peter 1:2. Peter was greeting the “pilgrims of the Dispersion [in Greek, diaspora]” (verse 1). He was specifically addressing the Jews outside the land of Israel, who were “elect [or chosen] according to the foreknowledge of God the Father, in sanctification of the Spirit, for obedience and sprinkling of the blood of Jesus Christ.”
Notice that obedience comes before sprinkling. The blood is not sprinkled on the disobedient. The blood does not protect those who go out of the house. It protects only those who are behind the blood or covered by it. So, bear in mind, although there is perfect protection in the blood, it is for the obedient alone.