Recently there has been a renewed interest in testimonies of people who have been to heaven or hell and come back.
There is a precedent in scripture for spiritual or heavenly visits and/or visions. John, Paul, and several prophets to name a few. But even these only got a limited peek of only what God chose to show them and there were things that they saw that they were told to seal up and not speak about because they were reserved for a particular time when they should be revealed.
There are many folks with "there and back again" testimonies that are sincere and true according to what they remember seeing... However, spiritual experiences, by their very nature, tend to be beyond our comprehension, experience, ability to understand and explain.
It is our responsibility to test everything and prove all things to see if they are true. If it contradicts scripture, do not receive it. Satan can appear as an "angel of light" (2 Cor 11:14) and even if an angel from heaven brings another gospel, we are not to receive it (Gal 1:8).
Many of these folks are sincere and I do not question they are relaying, to the best of their ability, what they have seen to the best of their memory and understanding of what they believe to be true.
Keep in mind, however, that anyone can be sincerely wrong...
God does not change nor contradict Himself.
Some of the things people have seen may go beyond their capacity for explanation, so they will try to recall and explain things in a way that they can understand and relate to based on their background, upbringing, and training. So while God is consistent, an individual person's understanding of something spiritual can be incomplete or mis-interpreted.
This may account for why so many of even the most legitimate testimonies seem to contradict each other as well as scripture in some aspect or another.
Additionally, no single individual has seen everything there is to see, nor have they been "enlightened" and become conduits for "all truth". These individuals are authoritative only in the testimony of what they remember seeing and hearing, and should not be trying to answer any and all deep theological questions.
The best thing to do is to take encouragement in the things that support and reinforce scripture, but do not base your theology on any human feelings or experiences.
