Heb 2:14 Inasmuch then as the children have partaken of flesh and blood, He Himself likewise shared in the same, that through death He might destroy him who had the power of death, that is, the devil,
Satan had the power of death in the sense that he authored sin and became its promoter. Sin brings with it death. He went to the garden of Eden and brought death to man by his lies.
Joh 8:44 "You are of your father the devil, and the desires of your father you want to do. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it.
He also has the power of death by justly demanding it from God against sinners. He accuses sinners of their sins before God and demands that they be punished with death.
But Satan is overcome, loses its power to demand death against redeemed sinners, by the blood of the Lamb. Through the death and the shed blood of the Lord Jesus Christ, Satan's demands are justly met. The Lord Jesus says: "I already paid for them."
Re 12:9 So the great dragon was cast out, that serpent of old, called the Devil and Satan, who deceives the whole world; he was cast to the earth, and his angels were cast out with him.
10 Then I heard a loud voice saying in heaven, "Now salvation, and strength, and the kingdom of our God, and the power of His Christ have come, for the accuser of our brethren, who accused them before our God day and night, has been cast down.
11 "And they overcame him by the blood of the Lamb and by the word of their testimony, and they did not love their lives to the death.
