For the life of the flesh is in the blood, and I have given it for you on the altar to make atonement for your souls, for it is the blood that makes atonement by the life. (Lev. 17:11).
In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace… (Eph. 1:7).
According to Old Testament law, the blood of the prescribed animal sacrifice satisfied the justice of God since it meant that the death sentence for sin had been carried out. Death and blood were synonymous, as Alan Stibbs writes,
The Hebrew word for ‘blood,’ as the name for the red or purple fluid which circulates in men’s arteries and veins, also had in the common speech of the people of Old Testament times a further significance which is readily understandable. When Joseph’s brethren sold him to the merchantmen who were going to Egypt, they took Joseph’s coat and dipped it in blood and sent it to Jacob. The sight of the blood made Jacob say, ‘An evil beast hath devoured him’ (Gen. 37:31-33). So blood directly suggested death, particularly a violent death. For when blood becomes visible and begins to flow, it means that damage has been done to someone’s life; and when the blood is poured out in quantity and, so to speak, thought of in isolation as now separate from the body in which it flowed, it means that a life has been taken. So ‘blood’ became a word symbol for ‘death’. When the psalmist says, ‘What profit is there in my blood?’, he means, ‘What profit is there in my death?’ (Ps. 30:9).
To give one’s blood was to give one’s life, which was the consequence God placed upon sin, and the ransom price on the sinner.
The first command given to man included a warning of the consequence of disobedience: “you shall surely die” (Gen. 2:17). When Adam and Eve sinned, God put an animal to death—He shed its blood—in order that coverings could be made for their sin (Gen. 3:21). Thus, the foundation of a pattern was established: Sin results in death, blood must be shed to cover man’s sin, and God is the ultimate provider of the sacrifice. Levitical law served as a continual reminder of these truths.
As the result of sin, the sinner became responsible to bring his own sacrifice to God, and the sacrifice was put to death—its blood had to be shed. In some cases, the placement of the sinner’s hand upon the animal’s head signified the transfer of his sin to the animal, which was then put to death as a substitute (Lev. 4:24). Thousands of years later, through the prophet Ezekiel, God made it clear, again, that the responsibility for sin fell upon the individual sinner. The father was not to be held responsible for the sins of his son, nor the son for the sins of his father, but the soul who sins shall die (Ezek. 18:4). Blood must be shed for each person’s sin.
Therefore, when we open the New Testament, we find all the bloody sacrifices of the old system culminating at the cross of Calvary; the old foreshadowed the new. When God forgave the sins of the one who offered an acceptable sacrifice, in the acceptable manner, it is because God looked forward to the sacrifice’s perfect fulfillment in the eventual gift of His Son. This enabled Him to righteously exercise “divine forbearance” and pass over “former sins” (Rom. 3:25).
Consistent with the synonymous relationship of death and blood in the old sacrificial system, the “blood of Christ” entails all that Christ suffered on our behalf. Consequently, the purchase price of our being redeemed from the slave market of sin was nothing less than the violent death of the Son of God, for this is one reason He came to earth: For even the Son of Man came not to be served but to serve, and to give his life as a ransom for many (Mk. 10:45).
The repeated references to the blood of Jesus in the New Testament draw attention to the sufficiency of His death as the just consequence of Him receiving our sins imputed to Him, for “without the shedding of blood there is no forgiveness of sins” (Heb. 9:22). In other words, the death of Christ—our Passover Lamb—is the sole basis of the atonement for our sins and, therefore, our forgiveness (Jn. 1:29; 1 Cor. 5:7). This is why the Apostle Peter described the blood of Christ as “precious…like that of a lamb without blemish or spot.” (1 Pet. 1:19). As our Passover Lamb, Jesus alone made the payment that God’s justice required, and did so with His own blood. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace… (Eph. 1:7).
O, the blood of Jesus washes me.
O, the blood of Jesus shed for me.
What a sacrifice that saved my life!
Yes, the blood it is my victory. 
 Alan Stibbs, His Blood Works (Fearn, UK: Christian Focus Publications, 2011), 33-34.
 Kari Jobe, O, the Blood (Gateway Worship).