Jehovah’s Witnesses take Eccl. 9:5 out of context to teach that a person is in a state of unconsciousness until the time of the “resurrection,” when God will “recreate” them as long as they are in His memory. It is not wise to base essential doctrine on the Book of Ecclesiastes, but many aberrant “Christian” groups do so. Besides giving God’s viewpoint on matters, the Bible also relates many things said and done by others, some good, others not so good. For example, at Job 2:4, the Bible gives Satan’s viewpoint on a matter.
The Book of Ecclesiastes is a study in contrast between the secular, humanistic, materialistic viewpoint of man and the theistic viewpoint of God. The first 11 Chapters focus primarily on man’s viewpoint, and the 12th contains God’s. For example, Eccl. 3:19 says, “For the fate of the sons of men and the fate of beasts is the same…there is no advantage for man over beast, for all is vanity.” 10:1: “Dead flies make a perfumer’s oil stink, so a little foolishness is weightier than wisdom and honor.” 10:19: “Men prepare a meal for enjoyment, and wine makes life merry, and money is the answer to everything.” 11:9: “Rejoice, young man during your childhood, and let your heart be pleasant during the days of young manhood. And follow the impulses of your heart and the desires of your eyes.” These verses obviously do not set forth God’s view, and this is only a small sample of what you’ll find in the first 11 Chapters of this Book.
The Bible clearly teaches that a separation of body and spirit occurs at death. Paul said, “we are of good courage, I say, and prefer rather to be absent from the body and to be at home with the Lord.” (2 Cor. 5:8) He said, “But I am hard-pressed from both directions, having the desire to depart and be with Christ, for that is very much better.” (Phil. 1:23) When Stephen was being stoned, he called upon Jesus saying, “Lord Jesus, receive my spirit!” (Acts 7:59) Peter said, “I consider it right, as long as I am in this earthly dwelling, to stir you up by way of reminder, knowing that the laying aside of my earthly dwelling is imminent, as also our Lord Jesus Christ has made clear to me.” (2 Pet. 1:13-14) It is important to note that these men were saved believers in Christ Jesus. On the cross, Jesus said, “Father, into Thy hand I commit My spirit.” (Luke 23:46)
Jesus gave an illustration of the principle of separation of soul/spirit from body at death. In Luke 16:19-31 you can read Jesus’ words about the rich man and Lazarus. Both men died and went to Hades. Lazarus was in the “paradise” compartment of Hades (Abraham’s bosom), while the rich man was in the “torments” section. They were separated by a great gulf, and both were fully conscious. The illustration fits perfectly with ancient Jewish thought and the Hebrew Scriptures where the righteous patriarchs are referred to as going “down” to be with their fathers in peace or being gathered to their people, while the unrighteous dead are referred to in the OT as being in agony. The first case of such being said in the OT is concerning Abraham, who was told directly by God that he would “go to his fathers in peace, and he would be buried in a good old age.” (Gen. 15:15) The place of Abraham’s burial is also recorded in the OT, and it is nowhere near Ur of the Chaldees where his “fathers” were physically buried.
The illustration Jesus gave at Luke 16 was a true picture of the state of the dead at that time. However, following His death and resurrection, Jesus “ascended on high, You have led captive Your captives.” (Ps. 68:18; Eph. 4:8-10) Jesus emptied out the righteous side of Sheol and led them victoriously to heaven. After this point in the Bible, no righteous person is ever said to go down to rest with their fathers, but instead they go up to be with the Lord. There they await the time when they will follow Jesus when He returns to earth for His 1000-year reign. After this comes the eternal state, where they will inherit the new heavens and earth.
The gospel message is this: Jesus Christ was sent by the Father to this earth to take your sins (the times you’ve lied, the times you’ve stolen, the times you’ve had impure thoughts) upon Himself on the cross. His death cancelled your sin debt with God. Because He died in your place, you have forgiveness of your sins if you believe this and submit yourself to Him. "For God so loved the world, that He gave His only begotten Son, that whoever believes in Him shall not perish, but have eternal life.” (John 3:16) "Truly, truly, I say to you, he who hears My word, and believes Him who sent Me, has eternal life, and does not come into judgment, but has passed out of death into life.” (John 5:24) Jesus said to her, "I am the resurrection and the life; he who believes in Me will live even if he dies.” (John 11:25)