The Vertical Aspects of Near Death Experiences

How does one know if knowledge of prior lives is genuine as opposed to, for example, demonic? There are evil intelligences out there. That's been raised with near death experiences. Even the ones that seem real, how do we know where they came from? I've debated this before and one Christian was giving the argument that the memories were planted by a demon. You kind of need to give some credence to memories in order to have a coherent worldview which includes last year existing.