As explained in this answer, many Bible passages use the word “soul” to mean “person”. For example, when God breathed into Adam the breath of life he became a living soul (Genesis 2:7 KJV); when Adam breathed out for the last time he became a dead soul, i.e. he was a dead person. Dead people are unconscious (Ecclesiastes 9:5). When faithful people died in New Testament times they are described as sleeping, because they are waiting for the resurrection when, at the return of Jesus Christ to the earth, he will raise them from the dead and reward them with eternal life (John 5:28-29; 1 Corinthians 15:51-55).
Sometimes people are confused by the figurative language in Revelation where dead souls (people) appear to be conscious. For example:
Revelation 6:9-10 When he opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the witness they had borne. 10 They cried out with a loud voice, “O Sovereign Lord, holy and true, how long before you will judge and avenge our blood on those who dwell on the earth?”
In this verse, words are put in the mouths of the dead to emphasise the eagerness with which the faithful followers of Christ look forward to the promised time of blessing.