In Hebrews 2:14, “the children” are believers who have accepted the substitutionary spiritual death of Jesus Christ on the Cross on their behalf. “Partook of the same” is the aorist active indicative of μετέχω (metechō) and means an accurate association of the same. Jesus Christ took on the form of man with flesh and blood, but without an old sin nature due to the Virgin Birth.
"Therefore, since the children share in flesh and blood, He Himself likewise also partook of the same, that through death He might render powerless him who had the power of death, that is, the devil," (Hebrews 2:14, NASB)
“Through death” means through the instrumentality of death. “He might render powerless” is the aorist active subjunctive of καταργέω (katargeō) and means to abrogate, to cancel, to annul, to render null and void, to neutralize. The Cross resolved the Angelic Conflict. The Cross neutralized Satan, but didn’t destroy him. Rendering powerless is only effective to the one believing.
This explains how Satan became the ruler of this world. He did by getting man to die spiritually in the Garden of Eden. He did it by physical death where God permits Satan to remove certain believers under the Sin Unto Death. As a result, a number of children were born again. 1 Cor. 5:5.
"I have decided to deliver such a one to Satan for the destruction of his flesh, so that his spirit may be saved in the day of the Lord Jesus." (1 Corinthians 5:5, NASB)
The believer is released from Satan’s rulership and dominion when filled with the Holy Spirit. When carnal or in a state of sin, the believer’s soul is ruled by the sin nature and can be influenced by what is in the world that is ruled by Satan and his demons. Believers continue to live on the earth with God's grace resources available to them while filled of the Holy Spirit. This is the intended modus operandi in the devil’s world. Heb. 2:15.
"and might free those who through fear of death were subject to slavery all their lives." (Hebrews 2:15, NASB)
In Hebrews 2:15, “fear of death” is basic Satanic doctrine. Every time you find a believer fearing physical death, he has accepted a basic Satanic doctrine through demons. Satan neutralizes the believer in time because of fear of death or dying. You have no right to be afraid of death at any time. If you are not afraid of death, you are not afraid of life.
Jesus Christ did not become an angel. He took on the form of man. He became like Abraham who lived part of his life as a Gentile and part as a Jew. If victory was to be won in the realm of the human race, Jesus Christ had to become a member of the human race. Heb. 2:16.
"For assuredly He does not give help to angels, but He gives help to the descendant of Abraham." (Hebrews 2:16, NASB)