While I believe there is a scientific case for the legitimacy of near-death experiences (eg. the subject is clinically dead, experiences are generally much more vivid and intense than any dream or hypnotic experience, and knowledge of events that occurred while the person was under), why do these experiences theologically contradict each other? For instance, many have Universalist themes while others report very strong Christian themes about salvation only through Jesus Christ and eternal damnation for sinners and unbelievers. Not to mention all the experiences that fit into non-Christian faiths, from Pagan to Buddhist to Hindu to Muslim. Shouldn’t God represent absolute truths or are there many different spiritual truths and paths for different peoples that are all legitimate?
Christians struggle to offer an explanation for Universalist or non-Christian themes, but the same could be said of Universalists towards Christian themes in near-death experiences. While I lean towards Theosophy, it should not be dismissed that certain experiences go against Universal Salvation.
One interpretation I have heard is that people manifest their afterlife. Certainly, near-death experiences are the strongest evidence there is for the Divine and an afterlife. However, both Fundamentalist Christians and secularists have some hostility towards using science to prove the existence of God. Perhaps atheists fear a turn away from secularism back towards religion, or just view spiritual science as a distraction and superstitious, and Christian Fundamentalists may fear new religions forming.
Christian responses:
The Contradictory Recollections of Near-Death Experiences
Near-Death Experiences and Emerging Implications For Christian Theology
Theosophical/Universalist Responses:
My Experience in Coma by Dr. Eben Alexander
Near Death Experiences and the Law of Cycles
Neutral Academic Response:
Proof of Heaven? Controversy over Near-Death Experiences in American Christianity
The minority of NDEs that involve out-of-body experiences might be interrogated empirically, I suppose, if they regularly involved observing details the patient couldn't have known except through extra-sensory means. I don't think we have the right experimental setup to verify this, though.
https://mindmatters.ai/2021/03/physician-explains-why-he-takes-near-death-experiences-seriously/