This is the blood of the covenant that God commanded for you.Hebrews 9:20
There is a strange power in the very name of blood, and the sight of it is always moving. A kind heart cannot bear to see a sparrow bleed and, unless familiarized by use, turns away with horror at the slaughter of a beast. As to the blood of men, it is a consecrated thing: It is murder to shed it in anger; it is a dreadful crime to squander it in war. Is this solemnity occasioned by the fact that the blood is the life, and the shedding of it the token of death? We think so. When we rise to contemplate the blood of the Son of God, our awe is greater yet, and we shudder as we think of the guilt of sin and the terrible penalty that the Sin-bearer endured. Blood, always precious, is priceless when it streams from Immanuel's side.
The blood of Jesus seals the covenant of grace and makes it certain forever. Covenants of old were made by sacrifice, and the everlasting covenant was ratified in the same manner. What comfort that our salvation rests upon the sure foundation of divine commitments that cannot be dishonored! Salvation by the works of the law is a frail and broken vessel whose shipwreck is sure; but the covenant vessel fears no storms, for the blood ensures the whole. The blood of Jesus made His covenant valid. Wills are of no power unless the testators die.
In this light the soldier's spear is a blessed aid to faith, since it proved our Lord to be really dead. There can be no doubt about that matter, and we may boldly appropriate the legacies that He has left for His people. Happy are they who see their title to heavenly blessings assured to them by a dying Savior. But does this blood not speak to us? Does it not bid us sanctify ourselves unto Him by whom we have been redeemed? Does it not call us to newness of life and incite us to entire consecration to the Lord? O that the power of the blood might be known and felt in us tonight!