I’ve formed a few impressions about the fundamentals of human nature that I feel are highly pertinent to a discussion of an afterlife and related matters.
 
I haven’t yet been able to recall or determine after the fact who said it, but when I encountered the expression that “Man is a creature with his feet in the muck and his head in the stars,” I immediately recognized the truth and power in it.

I find it undeniable that we humans have a base side to our nature.  To see it, all we need to do is drive on the public highways.  Drivers are forever engaging in selfish little acts of competitive nastiness that don’t actually benefit them in any way, yet put their lives and those of people all around them at substantial risk.

On the other hand, I’ve never seen a despicable action that was not ultimately explainable by the same fundamental drives and motivations we all share.  This includes a memorably depraved and horrific crime whose origins I pondered painstakingly for a period of years, involving a man passing himself off as a minister and ultimately convincing another man to murder blameless strangers.