Then Moses called all the elders of Israel and said to them, "Go and select lambs for yourselves according to your clans, and kill the Passover lamb. Take a bunch of hyssop and dip it in the blood that is in the basin, and touch the lintel and the two doorposts with the blood that is in the basin. None of you shall go out of the door of his house until the morning. For the LORD will pass through to strike the Egyptians, and when he sees the blood on the lintel and on the two doorposts, the LORD will pass over the door and will not allow the destroyer to enter your houses to strike you. You shall observe this rite as a statute for you and for your sons forever. And when you come to the land that the LORD will give you, as he has promised, you shall keep this service. And when your children say to you, 'What do you mean by this service?' you shall say, 'It is the sacrifice of the LORD's Passover, for he passed over the houses of the people of Israel in Egypt, when he struck the Egyptians but spared our houses.'" And the people bowed their heads and worshiped. Then the people of Israel went and did so; as the LORD had commanded Moses and Aaron, so they did.
Exodus 12:21-28
The lesson that we are to draw from the Passover story which is so critical for spiritual life is that there can be no real substitution without identification. The faith in the sprinkled blood that brought protection to Israel also brought them into the closest possible relation of obedience to God. And in the New Testament this is categorically emphasised: 'We thus judge that if one died for all (substitution), then were all dead (identification); and He died for all that they which live should not henceforth live unto themselves, but unto Him' (2 Corinthians 5:14, 15). A faith in Christ which does not recognize that we die in Him is less than biblical; a faith that does not bring us into union with Him is a faith that does not justify and does not save. It is this identification alone that safeguards faith in something entirely outside oneself from degenerating into an empty and amoral superstition, offensive to God and man alike.