This post is about consciousness and NDEs. If you want a summary of the typical set of events that occur during an NDE, you might like to read this post, which succinctly describes them.
People who have had an NDE usually report and believe that their disembodied consciousness or soul departed their body, and visited a heavenly reality beyond Earth.
They report that the NDE world has very different characteristics compared to the material world. For one thing, time behaves differently: there is no linear time in the heavenly sphere, and events tend to occur in parallel. They say Heaven is not exactly timeless; there is a sort of time, but it is not standard earthly linear time, and multiple things happen at once.
As an example of this non-linear time, it is common to have a full life review during an NDE, where every event in your life is examined. However, this review does not occur in temporal order; rather, every life event is examined simultaneously in parallel. Your whole life is reviewed in a flash of parallel processing.
The various unusual characteristics of the NDE realm make people who have had an NDE believe that they have died and gone to a most wonderful heavenly place which is distinct from regular earthly reality. Even former atheists may become convinced of this.
There is no pain or suffering in the heavenly sphere; everything is perfect, blissful, and euphoric. So most people do not want to return to Earth, because they are so happy in the heavenly realm.
Now, of course, the sceptics will have none of that, and claim that the entire NDE is a dream, hallucination, or some other altered state of consciousness that occurs in the physical brain. They argue that the individual's consciousness did not leave their body and travel to some other dimension; but rather, the whole experience was generated by the brain under low oxygen conditions (many NDEs occur when the heart stops for several minutes, or there is some other blockage of oxygen to the brain).
And of course, nobody can prove this either way.
But then, when you think about it, does it really matter? From the point of view of the person experiencing the NDE phenomenon that occurs as you die, they are enjoying a most beautiful, blissful, euphoric reality. They are in paradise, and because time does not flow linearly in this rapturous wonderland, there is no limit to how long they can stay.
So I am thinking: there is no doubt that the NDE phenomenon exists; it has been reported by thousands, if not millions, of people, and as far back as antiquity. Thus, even if it is generated by the physical brain, that does not make it any less of a paradise.
And even if your deceased brain might only be able to generate this NDE reality for a short time (eg a few days or weeks) before the brain physically deteriorates and ceases to function, because the NDE reality has timeless qualities, a few days of Earth time may correspond to a near eternal life in the NDE realm.
So it seems to me that, assuming everyone has an NDE after dying, we are all guaranteed an eternal life in paradise - even if that paradise is generated by the brain.