Why is the shedding of Christ's blood essential for the New Covenant?

According to Hebrews 9:16-17, a covenant is only effective after the death of the testator, which is crucial for the inheritance to be valid. The blood of Christ is the basis of the New Covenant, symbolizing the fulfillment of God's promise to redeem His people. This blood purifies not merely ceremonially, as in the old covenant sacrifices, but spiritually, cleansing our consciences from acts leading to death (Hebrews 9:14). Only through His sacrificial death can the eternal inheritance be imparted to those who are called, sealing our status as heirs in the grace of God.