According to Origen, considered to be the greatest Christian theologian (before he joined the doctors), said, "After death, I think the saints go to Paradise, a place of teaching, a school of the spirits, in which everything they saw on Earth will be made clear to them. Those who were pure in heart will progress more rapidly, reaching the kingdom of heaven by definite steps or degrees." Hell, according to the Pistis Sophia (an early Christian writing) (Leiden: Brill, 1978), is what lies in the opposite direction from that of progress, a state of inert and helpless being.
Most of the early Christian writings found in non-canonical texts clearly support the idea that the spirits of men continue on after death. Many of them are Gnostic writings, which contain many Christian teachings and many non-Christian teachings. Other writings that are more orthodox, such as the Coptics, also indicate life immediately after death."Beyond the veil are the heavens," says one (N. Sed, Revue des Etudes Juives 124 (1965): 39) and thus it is that not only, in the words of one scholar, "is God rendered invisible by the impenetrable veil of light that surrounds him," so are the realms that separate us from those who have passed on. These early teachings are also mirrored in near death experiences of our own day. People often report a brilliant white light through which they pass before seeing loved ones. Having researched many of these stories, they are simply too much alike regardless of culture and religion.
Years ago, when I took theology courses, we studied the issue of whether people had spirits. Our professor conceded the issue could be argued either way and he went through all the variations of word translations. In the end, though, the doctrine that people had spirits got the overwhelming nod. The arguments are just superior.
Jehovah's Witnesses are probably forbidden from researching things like near death experiences, but the bottom line is just too conclusive. "But we all, with open face beholding as in a glass the glory of the Lord, are changed into the same image from glory to glory, even as by the Spirit of the Lord." (2 Cor. 3:18) It's difficult to believe that man can make all these changes in this life. First, the scripture says "we all" (meaning all of us) are changed into the same image as Christ (not Adam) step by step. It's tough to do that here on present day Earth. And Acts 23:8 states: "For the Sadducees say that there is no resurrection, neither angel, nor spirit: but the Pharisees confess both." If the meaning of the word is "breath" it wouldn't make sense, as the Sadducees admitted breath, but not spirit. Acts 7:59 reports: "And they stoned Stephen, calling upon God, and saying, Lord Jesus, receive my spirit." If the meaning was "breath," it wouldn't make much sense.
There are many more, but the WTS is just wrong on this issue.