During a near death experience (NDE) or an out-of-body experience (OBE), people feel an expansion of consciousness beyond the body. At that time they become aware that our usual mental state is very limited in its ability to perceive. The expansive perception is usually accompanied by a feeling of 'timelessness'.  They feel that the past, present and future are all present at the same time.  This feeling gives them the understanding that the linear dimensional movement of time associated with the conventional neurology is a kind of illusion.  That is why they lose the fear of death.

The perception of universal consciousness removes the self-importance arising out of the illusory separateness of the individual from the other manifestations.  That is why they come back to tell us about the unqualified love they feel over there - it is possible only if the separateness feeling is washed away. 

Now the question is:  Can we move into the universal consciousness without there having to be a NDE or OBE?  The messages of Enlightened Beings, such as Ramana Maharishi and J Krishnamurti, do exhort us to take the journey into ourselves so that at some point along it, the universal consciousness rushes in and frees us from the illusory mind which is responsible for all unhappiness.