God made man in His Own Image and Likeness, so Adam was made like his Father. He was a spirit that is eternal and had an immortal body. Adam was never meant to die, either spiritually or physically. Rom.5:12(Amp) tells us, "Therefore, as sin came into the world through one man, and death a result of sin, so death spread to all men (no one) being able to stop it or to escape its power because all men sinned." Most people believe that it's because of what we've done, that makes us sinners. We're sinners because of being born of Adam, who was the seed that produced all men after the fall in the Garden of Eden. Paul tells us in Rom 5:12, "So death spread to all men, (no one) being able to stop it or escape its power."
God tells us in Lev.17:11(Amp), "The life (the animal soul) is in the blood, and I have given it to you upon the altar to make atonement for your souls, for it is the blood that makes atonement by reason of the life (which it represents)." Even though the spirit of man was still dead to God, the Blood of an Innocent Lamb would cover the sin of the spirit and give Life to his natural body. The life of the flesh is in the blood.
The word "atonement," is not used when speaking of the Blood of Jesus, because His Blood didn't cover our sin, it remitted and and removed our sins. When we got saved, the Life that is the Blood of Jesus has extended life in our natural bodies. Gen.6:3(Amp) says, "The the Lord said, 'My Spirit will not forever dwell and strive with man, for he also is flesh, but his days shall yet be 120 years, but the life of the flesh is in the Blood." With more Revelation about the Blood of Jesus, we could truly understand that "By His stripes we are healed." The stripes Jesus endured also shed blood, along with the nails, beatings and crown of thorns.
His Spirit was separated from the Father, when Jesus died on the cross. God told Cain in Gen.4:10(Amp), "Your brother's blood calls out to me from the ground." The Blood of Jesus is crying out to and for us from the Mercy Seat in the Heavenly Holy of Holies and it continues to extend the life of our flesh today. Much of what we understand about the Blood of our Innocent Sacrifice Lamb and its Power in our lives in this world and in our natural bodies, relates to our physical healing. Jesus told His followers, "You are in this world, but not of this world." We still need to maintain our bodies, in order to do the work we were designed to do while in this world. The Blood of Jesus' flesh is still the Life of our flesh. It has destroyed the sin factor that caused death and disease. It also extends the natural body by its place on the Mercy Seat in Heaven.
Sickness and disease are still here and are why many of us die. So long as they listened diligently to the Lord, we see no sign of sickness and disease in the Blessing of the Covenant found in Deut.28. In the latter part of the Blessing, we see how the people weren't obedient to listen diligently to the Lord and instead walked in their own understanding, the people were destroyed by sickness, disease and calamity of the Curse that was already here.
Jesus said in Matt.15:6(Amp), "So for the sake of your tradition (rules handed down by your forefathers), you have set aside the Word of God (depriving it of force and authority and making it of no effect)." The people were still offering sacrifices, without believing what God had said. Their offerings were something they did as a religion and tradition, so their had no life in the blood. When we spend one on One time with God, we will better understand why Christians are still vulnerable to many things of this world. When we pray in the Spirit, we're speaking mysteries unto God and not to men. God will reveal mysteries to us, that will change how we see His Word. We might not live to 120 years, but we don't have to check out at 70 or 75 years. We must take the Life of the flesh that is in the Blood of Jesus and renew our minds by His Word and one on One fellowship with our Heavenly Father.