The Greek word for Sheol means essentially the same, the word is Hades. It appears only ten times in the New Testament and is defined by the scholar Thayer as “the nether (lower) world, the realm of the dead.” Hades, taken in its most general sense was the place of assembly and residence for all who departed from the present world before Christ came. The classical Greek writers considered Hades to be divided into two parts. The upper part the “Elysian fields”, the abode of the good, the lower part, just lower down, was tartaros, the place of punishment for the wicked.
When Christ went to the Hadean world He re-made its constituency. He took from its borders the souls that were “under altars who had cried; ‘How long, O Lord, holy and true, dost Thou not judge and avenge our blood on them that dwell on the earth?” Revelation 6:10 There are some who do not understand Matthew 16:18 where Jesus said; “and I also say unto thee, that thou art Peter, and upon this rock I will build My church and the gates of Hades shall not prevail against it.” Gates, here, indicate a closure that would keep one in Hades. Jesus went to Hades when He died, but it did not contain Him; He came forth to complete His appointed rendezvous with God the Father. Coming forth from the grave, Christ opened the graves; and many bodies of the saints which slept arose, and came out of the graves after His resurrection, and went into the holy city, and appeared unto many.” Matthew 27:52-53 These were they to whom Moses had delivered a message when he returned from the Mount of Transfiguration where he had been with Jesus and Elijah discussing Christ decease that was to be accomplished outside the city of Jerusalem!(Luke 9:31), they who were stirred (aroused to overthrow Satan in his own kingdom, Revelation 12:7-10) up for Him, even all the chief ones of the earth; it had raised up from their thrones all the kings of the nations”, Isaiah 14:9, when Christ came epitomized as Michael the arch angel- when He went to claim they who were His(in the Hadean realm, the heart of the earth)!! As Paul writes: “Now that He ascended, what is it but that He also first descended into the lower parts of the earth (He went into the Hadean world)? He that descended is the same also that ascended up far above all heavens (He went above the heavens above us and the heavens of outer space), that He might fill all things (fulfill all prophecies made concerning Him). (And when He ascended) He gave (sent the Holy Spirit, who empowered) some, apostles, and some prophets; and some, evangelists, and some, pastors and teachers. For the perfecting of the saints (delivering of His New Testament), for the work of the ministry (through the laying on of the hands of the apostles, men were empowered to teach the saved); for the edifying of the body of Christ: TILL we all come (had received) the unity (fullness, the entirety- “when that which was perfect HAD COME”, when the “faith was once and for all delivered to the saints” ) of the faith, and of the knowledge of the Son of God (so we could “know Him (understand why He had to die), and the power of His resurrection (what this means to us in receiving the forgiveness of sins through His blood), and fellowship of His sufferings (“all who live godly in Christ Jesus shall suffer persecution”), being made conformable (we might receive a spiritual body, the likeness in which He resides) unto His death); as a perfect (mature) man, unto the measure (totality) of the stature (complete intention of God the Father concerning Jesus Christ) of the fullness (the entire purpose for which) Christ came.” Ephesians 4:8-13
“Because He will not leave My soul in Hades, neither wilt Thou allow Thy Holy One to see corruption (which begins on the fourth day in the grave)”Acts 2:27-31,Ps 16:10