How do we know the importance of Christ's sacrifice from the Old Testament?

The Old Testament contains numerous types and shadows that foreshadow the ultimate sacrifice of Jesus Christ. Abel's offering is a prime example; he presented a blood offering, recognizing the requirement of atonement for sin. This act with lambs pointed to Christ, who would later fulfill the need for sacrificial atonement by shedding His blood for the sins of His people. The sacrificial system established in the law illustrates God's justice and mercy, wherein the innocent dies for the guilty. This principle runs throughout Scripture, culminating in the New Testament wherein Christ is revealed as the Lamb of God, satisfying divine justice and offering reconciliation for sinners.